[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-ppc64le-linux-multistage` running on `ppc64le-clang-multistage-test` while building `llvm` at step 5 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/76/builds/735

Here is the relevant piece of the build log for the reference:
```
Step 5 (ninja check 1) failure: stage 1 checked (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/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llc -verify-machineinstrs -mtriple=aarch64-none-linux-gnu      -start-before aarch64-sls-hardening -o - /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir      -asm-verbose=0  | /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/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/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/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/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llc -verify-machineinstrs -mtriple=aarch64-none-linux-gnu -start-before aarch64-sls-hardening -o - /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/AArch64/speculation-hardening-sls-blra.mir -asm-verbose=0
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/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llc -verify-machineinstrs -mtriple=aarch64-none-linux-gnu -start-before aarch64-sls-hardening -o - /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/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/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/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 0x00007fff920829b0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/../lib/libLLVMSupport.so.19.0git+0x2329b0)
 #1 0x00007fff9207f714 SignalHandler(int) Signals.cpp:0:0
 #2 0x00007fff9c6804d8 (linux-vdso64.so.1+0x4d8)
 #3 0x00007fff943b1794 llvm::MachineInstr::addOperand(llvm::MachineFunction&, llvm::MachineOperand const&) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/../lib/libLLVMCodeGen.so.19.0git+0x471794)
 #4 0x00007fff9b6f0894 llvm::ThunkInserter<(anonymous namespace)::SLSHardeningInserter, (anonymous namespace)::ThunksSet>::run(llvm::MachineModuleInfo&, llvm::MachineFunction&) AArch64SLSHardening.cpp:0:0
 #5 0x00007fff943985dc llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.70) MachineFunctionPass.cpp:0:0
 #6 0x00007fff925db8f0 llvm::FPPassManager::runOnFunction(llvm::Function&) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/../lib/libLLVMCore.so.19.0git+0x33b8f0)
 #7 0x00007fff925dbc38 llvm::FPPassManager::runOnModule(llvm::Module&) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/../lib/libLLVMCore.so.19.0git+0x33bc38)
 #8 0x00007fff925dcb68 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/../lib/libLLVMCore.so.19.0git+0x33cb68)
 #9 0x000000001001d5bc compileModule(char**, llvm::LLVMContext&) llc.cpp:0:0
#10 0x0000000010011398 main (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llc+0x10011398)
#11 0x00007fff918aa96c generic_start_main.isra.0 (/lib64/libc.so.6+0x2a96c)
#12 0x00007fff918aab04 __libc_start_main (/lib64/libc.so.6+0x2ab04)
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/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