[llvm] [DebugInfo][RemoveDIs] Remove some debug intrinsic-only codepaths (PR #143451)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `mlir-nvidia` running on `mlir-nvidia` while building `llvm` at step 7 "test-build-check-mlir-build-only-check-mlir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/138/builds/14391

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

```
Step 7 (test-build-check-mlir-build-only-check-mlir) failure: test (failure)
******************** TEST 'MLIR :: Target/LLVMIR/omptarget-debug-var-1.mlir' FAILED ********************
Exit Code: 2

Command Output (stdout):
--
# RUN: at line 1
/vol/worker/mlir-nvidia/mlir-nvidia/llvm.obj/bin/mlir-translate -mlir-to-llvmir /vol/worker/mlir-nvidia/mlir-nvidia/llvm.src/mlir/test/Target/LLVMIR/omptarget-debug-var-1.mlir | /vol/worker/mlir-nvidia/mlir-nvidia/llvm.obj/bin/FileCheck /vol/worker/mlir-nvidia/mlir-nvidia/llvm.src/mlir/test/Target/LLVMIR/omptarget-debug-var-1.mlir
# executed command: /vol/worker/mlir-nvidia/mlir-nvidia/llvm.obj/bin/mlir-translate -mlir-to-llvmir /vol/worker/mlir-nvidia/mlir-nvidia/llvm.src/mlir/test/Target/LLVMIR/omptarget-debug-var-1.mlir
# .---command stderr------------
# | mlir-translate: /vol/worker/mlir-nvidia/mlir-nvidia/llvm.src/llvm/lib/IR/BasicBlock.cpp:63: void llvm::BasicBlock::convertToNewDbgValues(): Assertion `!I.DebugMarker && "DebugMarker already set on old-format instrs?"' failed.
# | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
# | Stack dump:
# | 0.	Program arguments: /vol/worker/mlir-nvidia/mlir-nvidia/llvm.obj/bin/mlir-translate -mlir-to-llvmir /vol/worker/mlir-nvidia/mlir-nvidia/llvm.src/mlir/test/Target/LLVMIR/omptarget-debug-var-1.mlir
# | Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
# | 0  libLLVMSupport.so.21.0git                         0x00007c27d5da91a7 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 39
# | 1  libLLVMSupport.so.21.0git                         0x00007c27d5da6d3e llvm::sys::RunSignalHandlers() + 238
# | 2  libLLVMSupport.so.21.0git                         0x00007c27d5da98c5
# | 3  libc.so.6                                         0x00007c27d565b520
# | 4  libc.so.6                                         0x00007c27d56af9fc pthread_kill + 300
# | 5  libc.so.6                                         0x00007c27d565b476 raise + 22
# | 6  libc.so.6                                         0x00007c27d56417f3 abort + 211
# | 7  libc.so.6                                         0x00007c27d564171b
# | 8  libc.so.6                                         0x00007c27d5652e96
# | 9  libLLVMCore.so.21.0git                            0x00007c27d70f81b0 llvm::BasicBlock::convertToNewDbgValues() + 752
# | 10 libLLVMCore.so.21.0git                            0x00007c27d72086be llvm::Function::convertToNewDbgValues() + 46
# | 11 libMLIRTargetLLVMIRExport.so.21.0git              0x00007c27db7f27de
# | 12 libMLIRTargetLLVMIRExport.so.21.0git              0x00007c27db7f2437 mlir::translateModuleToLLVMIR(mlir::Operation*, llvm::LLVMContext&, llvm::StringRef, bool) + 2471
# | 13 libMLIRToLLVMIRTranslationRegistration.so.21.0git 0x00007c27dea4838f
# | 14 libMLIRTranslateLib.so.21.0git                    0x00007c27db7611b6
# | 15 libMLIRTranslateLib.so.21.0git                    0x00007c27db75f28e
# | 16 libMLIRSupport.so.21.0git                         0x00007c27d5e25e18 mlir::splitAndProcessBuffer(std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, llvm::function_ref<llvm::LogicalResult (std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, llvm::raw_ostream&)>, llvm::raw_ostream&, llvm::StringRef, llvm::StringRef) + 808
# | 17 libMLIRTranslateLib.so.21.0git                    0x00007c27db75b79c mlir::mlirTranslateMain(int, char**, llvm::StringRef) + 556
# | 18 mlir-translate                                    0x0000574b803d1dff
# | 19 libc.so.6                                         0x00007c27d5642d90
# | 20 libc.so.6                                         0x00007c27d5642e40 __libc_start_main + 128
# | 21 mlir-translate                                    0x0000574b803d1cf5
# `-----------------------------
# error: command failed with exit status: -6
# executed command: /vol/worker/mlir-nvidia/mlir-nvidia/llvm.obj/bin/FileCheck /vol/worker/mlir-nvidia/mlir-nvidia/llvm.src/mlir/test/Target/LLVMIR/omptarget-debug-var-1.mlir
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line:  /vol/worker/mlir-nvidia/mlir-nvidia/llvm.obj/bin/FileCheck /vol/worker/mlir-nvidia/mlir-nvidia/llvm.src/mlir/test/Target/LLVMIR/omptarget-debug-var-1.mlir
# `-----------------------------
# error: command failed with exit status: 2

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/143451