[llvm] [llvm-dlltool] Implement the --identify option (PR #127465)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `amdgpu-offload-ubuntu-22-cmake-build-only` running on `rocm-docker-ubu-22` while building `llvm` at step 4 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/203/builds/2463

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 4 (annotate) failure: '../llvm-zorg/zorg/buildbot/builders/annotated/amdgpu-offload-cmake.py --jobs=32' (failure)
...
[4774/7657] Building CXX object tools/clang/lib/Basic/CMakeFiles/obj.clangBasic.dir/Targets/PNaCl.cpp.o
[4775/7657] Linking CXX shared library lib/libMLIRAffineAnalysis.so.21.0git
[4776/7657] Building CXX object tools/clang/lib/Basic/CMakeFiles/obj.clangBasic.dir/Targets/NVPTX.cpp.o
[4777/7657] Building CXX object tools/clang/lib/Basic/CMakeFiles/obj.clangBasic.dir/Targets/PPC.cpp.o
[4778/7657] Creating library symlink lib/libMLIRControlFlowToSCF.so
[4779/7657] Linking CXX shared library lib/libLLVMInterfaceStub.so.21.0git
[4780/7657] Creating library symlink lib/libLLVMInterfaceStub.so
[4781/7657] Linking CXX shared library lib/libMLIRMLProgramTransforms.so.21.0git
[4782/7657] Creating library symlink lib/libMLIRAffineAnalysis.so
[4783/7657] Linking CXX shared library lib/libLLVMDlltoolDriver.so.21.0git
FAILED: lib/libLLVMDlltoolDriver.so.21.0git 
: && /usr/bin/c++ -fPIC -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -Wl,-z,defs -Wl,-z,nodelete   -Wl,-rpath-link,/home/botworker/bbot/amdgpu-offload-ubuntu-22-cmake-build-only/build/./lib  -Wl,--gc-sections -shared -Wl,-soname,libLLVMDlltoolDriver.so.21.0git -o lib/libLLVMDlltoolDriver.so.21.0git lib/ToolDrivers/llvm-dlltool/CMakeFiles/LLVMDlltoolDriver.dir/DlltoolDriver.cpp.o  -Wl,-rpath,"\$ORIGIN/../lib:/home/botworker/bbot/amdgpu-offload-ubuntu-22-cmake-build-only/build/lib:"  lib/libLLVMObject.so.21.0git  lib/libLLVMOption.so.21.0git  lib/libLLVMTargetParser.so.21.0git  lib/libLLVMSupport.so.21.0git  -Wl,-rpath-link,/home/botworker/bbot/amdgpu-offload-ubuntu-22-cmake-build-only/build/lib && :
/usr/bin/ld: lib/ToolDrivers/llvm-dlltool/CMakeFiles/LLVMDlltoolDriver.dir/DlltoolDriver.cpp.o: in function `(anonymous namespace)::doIdentify(llvm::StringRef, bool)':
DlltoolDriver.cpp:(.text._ZN12_GLOBAL__N_110doIdentifyEN4llvm9StringRefEb+0x174): undefined reference to `llvm::identify_magic(llvm::StringRef)'
/usr/bin/ld: DlltoolDriver.cpp:(.text._ZN12_GLOBAL__N_110doIdentifyEN4llvm9StringRefEb+0xabd): undefined reference to `llvm::identify_magic(llvm::StringRef)'
collect2: error: ld returned 1 exit status
[4784/7657] Linking CXX shared library lib/libMLIRVectorDialect.so.21.0git
[4785/7657] Linking CXX shared library lib/libMLIRCAPISCF.so.21.0git
[4786/7657] Linking CXX shared library lib/libLLVMLibDriver.so.21.0git
[4787/7657] Creating library symlink lib/libMLIRFuncAllExtensions.so
[4788/7657] Linking CXX shared library lib/libLLVMDebugInfoDWARF.so.21.0git
[4789/7657] Linking CXX shared library lib/libMLIRTosaDialect.so.21.0git
[4790/7657] Linking CXX shared library lib/libMLIRBufferizationTransforms.so.21.0git
[4791/7657] Linking CXX shared library lib/libMLIRAffineUtils.so.21.0git
[4792/7657] Linking CXX shared library lib/libMLIRShapeToStandard.so.21.0git
[4793/7657] Linking CXX shared library lib/libLLVMRuntimeDyld.so.21.0git
[4794/7657] Linking CXX shared library lib/libLLVMXRay.so.21.0git
[4795/7657] Linking CXX shared library lib/libLLVMDebugInfoPDB.so.21.0git
[4796/7657] Linking CXX shared library lib/libLLVMObjectYAML.so.21.0git
[4797/7657] Linking CXX shared library lib/libLLVMJITLink.so.21.0git
[4798/7657] Linking CXX shared library lib/libLLVMObjCopy.so.21.0git
[4799/7657] Building AMDGPUGenRegBankGICombiner.inc...
[4800/7657] Building AMDGPUGenPostLegalizeGICombiner.inc...
[4801/7657] Linking CXX shared library lib/libMLIRLinalgDialect.so.21.0git
[4802/7657] Building AMDGPUGenPreLegalizeGICombiner.inc...
[4803/7657] Linking CXX shared library lib/libMLIRSPIRVDialect.so.21.0git
[4804/7657] Building AMDGPUGenSubtargetInfo.inc...
[4805/7657] Building AMDGPUGenMCCodeEmitter.inc...
[4806/7657] Building AMDGPUGenSearchableTables.inc...
[4807/7657] Building AMDGPUGenDisassemblerTables.inc...
[4808/7657] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/AsmPrinter.cpp.o
[4809/7657] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTO.cpp.o
[4810/7657] Building AMDGPUGenAsmWriter.inc...
[4811/7657] Building AMDGPUGenAsmMatcher.inc...
[4812/7657] Building AMDGPUGenGlobalISel.inc...
[4813/7657] Building AMDGPUGenInstrInfo.inc...
[4814/7657] Building AMDGPUGenDAGISel.inc...
[4815/7657] Building AMDGPUGenRegisterInfo.inc...
[4816/7657] Building AMDGPUGenRegisterBank.inc...
Step 7 (build cmake config) failure: build cmake config (failure)
...
[4774/7657] Building CXX object tools/clang/lib/Basic/CMakeFiles/obj.clangBasic.dir/Targets/PNaCl.cpp.o
[4775/7657] Linking CXX shared library lib/libMLIRAffineAnalysis.so.21.0git
[4776/7657] Building CXX object tools/clang/lib/Basic/CMakeFiles/obj.clangBasic.dir/Targets/NVPTX.cpp.o
[4777/7657] Building CXX object tools/clang/lib/Basic/CMakeFiles/obj.clangBasic.dir/Targets/PPC.cpp.o
[4778/7657] Creating library symlink lib/libMLIRControlFlowToSCF.so
[4779/7657] Linking CXX shared library lib/libLLVMInterfaceStub.so.21.0git
[4780/7657] Creating library symlink lib/libLLVMInterfaceStub.so
[4781/7657] Linking CXX shared library lib/libMLIRMLProgramTransforms.so.21.0git
[4782/7657] Creating library symlink lib/libMLIRAffineAnalysis.so
[4783/7657] Linking CXX shared library lib/libLLVMDlltoolDriver.so.21.0git
FAILED: lib/libLLVMDlltoolDriver.so.21.0git 
: && /usr/bin/c++ -fPIC -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -Wl,-z,defs -Wl,-z,nodelete   -Wl,-rpath-link,/home/botworker/bbot/amdgpu-offload-ubuntu-22-cmake-build-only/build/./lib  -Wl,--gc-sections -shared -Wl,-soname,libLLVMDlltoolDriver.so.21.0git -o lib/libLLVMDlltoolDriver.so.21.0git lib/ToolDrivers/llvm-dlltool/CMakeFiles/LLVMDlltoolDriver.dir/DlltoolDriver.cpp.o  -Wl,-rpath,"\$ORIGIN/../lib:/home/botworker/bbot/amdgpu-offload-ubuntu-22-cmake-build-only/build/lib:"  lib/libLLVMObject.so.21.0git  lib/libLLVMOption.so.21.0git  lib/libLLVMTargetParser.so.21.0git  lib/libLLVMSupport.so.21.0git  -Wl,-rpath-link,/home/botworker/bbot/amdgpu-offload-ubuntu-22-cmake-build-only/build/lib && :
/usr/bin/ld: lib/ToolDrivers/llvm-dlltool/CMakeFiles/LLVMDlltoolDriver.dir/DlltoolDriver.cpp.o: in function `(anonymous namespace)::doIdentify(llvm::StringRef, bool)':
DlltoolDriver.cpp:(.text._ZN12_GLOBAL__N_110doIdentifyEN4llvm9StringRefEb+0x174): undefined reference to `llvm::identify_magic(llvm::StringRef)'
/usr/bin/ld: DlltoolDriver.cpp:(.text._ZN12_GLOBAL__N_110doIdentifyEN4llvm9StringRefEb+0xabd): undefined reference to `llvm::identify_magic(llvm::StringRef)'
collect2: error: ld returned 1 exit status
[4784/7657] Linking CXX shared library lib/libMLIRVectorDialect.so.21.0git
[4785/7657] Linking CXX shared library lib/libMLIRCAPISCF.so.21.0git
[4786/7657] Linking CXX shared library lib/libLLVMLibDriver.so.21.0git
[4787/7657] Creating library symlink lib/libMLIRFuncAllExtensions.so
[4788/7657] Linking CXX shared library lib/libLLVMDebugInfoDWARF.so.21.0git
[4789/7657] Linking CXX shared library lib/libMLIRTosaDialect.so.21.0git
[4790/7657] Linking CXX shared library lib/libMLIRBufferizationTransforms.so.21.0git
[4791/7657] Linking CXX shared library lib/libMLIRAffineUtils.so.21.0git
[4792/7657] Linking CXX shared library lib/libMLIRShapeToStandard.so.21.0git
[4793/7657] Linking CXX shared library lib/libLLVMRuntimeDyld.so.21.0git
[4794/7657] Linking CXX shared library lib/libLLVMXRay.so.21.0git
[4795/7657] Linking CXX shared library lib/libLLVMDebugInfoPDB.so.21.0git
[4796/7657] Linking CXX shared library lib/libLLVMObjectYAML.so.21.0git
[4797/7657] Linking CXX shared library lib/libLLVMJITLink.so.21.0git
[4798/7657] Linking CXX shared library lib/libLLVMObjCopy.so.21.0git
[4799/7657] Building AMDGPUGenRegBankGICombiner.inc...
[4800/7657] Building AMDGPUGenPostLegalizeGICombiner.inc...
[4801/7657] Linking CXX shared library lib/libMLIRLinalgDialect.so.21.0git
[4802/7657] Building AMDGPUGenPreLegalizeGICombiner.inc...
[4803/7657] Linking CXX shared library lib/libMLIRSPIRVDialect.so.21.0git
[4804/7657] Building AMDGPUGenSubtargetInfo.inc...
[4805/7657] Building AMDGPUGenMCCodeEmitter.inc...
[4806/7657] Building AMDGPUGenSearchableTables.inc...
[4807/7657] Building AMDGPUGenDisassemblerTables.inc...
[4808/7657] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/AsmPrinter.cpp.o
[4809/7657] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTO.cpp.o
[4810/7657] Building AMDGPUGenAsmWriter.inc...
[4811/7657] Building AMDGPUGenAsmMatcher.inc...
[4812/7657] Building AMDGPUGenGlobalISel.inc...
[4813/7657] Building AMDGPUGenInstrInfo.inc...
[4814/7657] Building AMDGPUGenDAGISel.inc...
[4815/7657] Building AMDGPUGenRegisterInfo.inc...
[4816/7657] Building AMDGPUGenRegisterBank.inc...

```

</details>

https://github.com/llvm/llvm-project/pull/127465