[llvm] [AArch64][PAC] Support BLRA* instructions in SLS Hardening pass (PR #97605)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64be-linux-test-suite` running on `ppc64be-clang-test-suite` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/176/builds/791

Here is the relevant piece of the build log for the reference:
```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/AArch64/speculation-hardening-sls-blra.mir' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
RUN: at line 1: /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/llc -verify-machineinstrs -mtriple=aarch64-none-linux-gnu      -start-before aarch64-sls-hardening -o - /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/llvm-project/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir      -asm-verbose=0  | /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/llvm-project/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir      --implicit-check-not=__llvm_slsblr_thunk_aa_x5_x8      --implicit-check-not=__llvm_slsblr_thunk_ab_x5_x8      --implicit-check-not=__llvm_slsblr_thunk_aaz_x5      --implicit-check-not=__llvm_slsblr_thunk_abz_x5
+ /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/llc -verify-machineinstrs -mtriple=aarch64-none-linux-gnu -start-before aarch64-sls-hardening -o - /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/llvm-project/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir -asm-verbose=0
+ /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/llvm-project/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir --implicit-check-not=__llvm_slsblr_thunk_aa_x5_x8 --implicit-check-not=__llvm_slsblr_thunk_ab_x5_x8 --implicit-check-not=__llvm_slsblr_thunk_aaz_x5 --implicit-check-not=__llvm_slsblr_thunk_abz_x5
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/llc -verify-machineinstrs -mtriple=aarch64-none-linux-gnu -start-before aarch64-sls-hardening -o - /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/llvm-project/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir -asm-verbose=0
1.	Running pass 'Function Pass Manager' on module '/home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/llvm-project/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir'.
2.	Running pass 'AArch64 sls hardening pass' on function '@__llvm_slsblr_thunk_aa_x0_x1'
 #0 0x000000001442d298 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/llc+0x1442d298)
 #1 0x000000001442a16c SignalHandler(int) Signals.cpp:0:0
 #2 0x00003fff91ef0478 (+0x478)
 #3 0x00003fffcaa87be0 
 #4 0x0000000010a0ce54 llvm::ThunkInserter<(anonymous namespace)::SLSHardeningInserter, (anonymous namespace)::ThunksSet>::run(llvm::MachineModuleInfo&, llvm::MachineFunction&) AArch64SLSHardening.cpp:0:0
 #5 0x0000000012f5875c llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
 #6 0x000000001371e528 llvm::FPPassManager::runOnFunction(llvm::Function&) (/home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/llc+0x1371e528)
 #7 0x000000001371e858 llvm::FPPassManager::runOnModule(llvm::Module&) (/home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/llc+0x1371e858)
 #8 0x000000001371f4d4 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/llc+0x1371f4d4)
 #9 0x00000000103f541c compileModule(char**, llvm::LLVMContext&) llc.cpp:0:0
#10 0x00000000102f0e58 main (/home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/llc+0x102f0e58)
#11 0x00003fff91917cec generic_start_main.isra.0 libc-start.c:0:0
#12 0x00003fff91917ef4 __libc_start_main (/lib64/libc.so.6+0x47ef4)
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/build/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64be-clang-test-suite/clang-ppc64be-test-suite/llvm-project/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir --implicit-check-not=__llvm_slsblr_thunk_aa_x5_x8 --implicit-check-not=__llvm_slsblr_thunk_ab_x5_x8 --implicit-check-not=__llvm_slsblr_thunk_aaz_x5 --implicit-check-not=__llvm_slsblr_thunk_abz_x5

--

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


```

https://github.com/llvm/llvm-project/pull/97605