[SPIRV][Mesa][LLVMPIPE] reversebits 16 bit is crashing the driver

Nobody has claimed this yet.

```bash
offloader -debug-layer -adapter-substring="llvmpipe" Output/reversebits.16.test.tmp/pipeline.yaml Output/reversebits.16.test.tmp.o
```

```gdb
#0 0x0000568b8d38b7d8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /mnt/DevDrive/projects/llvm-project/llvm/lib/Support/Unix/Signals.inc:842:13
#1 0x0000568b8d389383 llvm::sys::RunSignalHandlers() /mnt/DevDrive/projects/llvm-project/llvm/lib/Support/Signals.cpp:109:18
#2 0x0000568b8d38c561 SignalHandler(int, siginfo_t*, void*) /mnt/DevDrive/projects/llvm-project/llvm/lib/Support/Unix/Signals.inc:429:38
#3 0x00007fd1cde45330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
#4 0x00007fd1c782e61b (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x442e61b)
#5 0x00007fd1c495feaa (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x155feaa)
#6 0x00007fd1c4960ebd (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x1560ebd)
#7 0x00007fd1c495cf08 (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x155cf08)
#8 0x00007fd1c495e8ce (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x155e8ce)
#9 0x00007fd1c4843c23 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x1443c23)
#10 0x00007fd1c458869f llvm::FPPassManager::runOnFunction(llvm::Function&) (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x118869f)
#11 0x00007fd1c458e614 llvm::FPPassManager::runOnModule(llvm::Module&) (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x118e614)
#12 0x00007fd1c4588ea7 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x1188ea7)
#13 0x00007fd1c62932b2 llvm::MCJIT::emitObject(llvm::Module*) (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x2e932b2)
#14 0x00007fd1c62934de llvm::MCJIT::generateCodeForModule(llvm::Module*) (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x2e934de)
#15 0x00007fd1c6293e7d llvm::MCJIT::finalizeObject() (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x2e93e7d)
#16 0x00007fd1c6202547 LLVMGetPointerToGlobal (/lib/x86_64-linux-gnu/libLLVM.so.20.1+0x2e02547)
#17 0x00007fd1cc209842 (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0x409842)
#18 0x00007fd1cc0daa83 (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0x2daa83)
#19 0x00007fd1cc0dbe64 (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0x2dbe64)
#20 0x00007fd1cbed67b4 (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0xd67b4)
#21 0x00007fd1cbed9aba (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0xd9aba)
#22 0x00007fd1cbec675c (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0xc675c)
#23 0x00007fd1cbe824a6 (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0x824a6)
#24 0x00007fd1cbe8275e (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0x8275e)
#25 0x00007fd1cbf7618c (/usr/lib/x86_64-linux-gnu/libvulkan_lvp.so+0x17618c)
#26 0x00007fd1cde9caa4 start_thread ./nptl/pthread_create.c:447:8
#27 0x00007fd1cdf29c6c clone3 ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:80:0
/mnt/DevDrive/projects/llvm_builds/llvm_rel_with_debug_offload/tools/OffloadTest/test/clang-vk/Feature/HLSLLib/Output/reversebits.16.test.script: line 3: 3140458 Segmentation fault
```

Start by running the provided offloader command with the llvmpipe adapter against Output/reversebits.16.test.tmp/pipeline.yaml and its object file. Use the stack trace and reversebits.16.test.script as the initial investigation points; done means this test no longer causes the Mesa llvmpipe driver to segfault.

Written by the indexing model from the issue text.