LLVM12 issue: clang: CommandLine Error: Option 'h' registered more than once!

[Dongwon Kim]

With following packages installed on top of Ubuntu 22.04LTS related to OpenCL on intel GFX.

libllvm12:amd64 <none> 1:12.0.1-19ubuntu3
libclang-cpp12:amd64 <none> 1:12.0.1-19ubuntu3
libllvmspirvlib12:amd64 <none> 12.0.0-3
libopencl-clang12:amd64 <none> 12.0.0-3
libigc1:amd64 <none> 1.0.10840-1
libigc-tools:amd64 <none> 1.0.10840-1
libclang1-12:amd64 <none> 1:12.0.1-19ubuntu3
libigdgmm12:amd64 <none> 22.1.2+ds1-1
libigdfcl1:amd64 <none> 1.0.10840-1
ocl-icd-libopencl1:amd64 <none> 2.2.14-3
intel-opencl-icd:amd64 <none> 22.14.22890-1

Subtests from standard Khronos OpenCL-CTS at https://github.com/KhronosGroup/OpenCL-CTS sporadically fails with an error,

Executed command : "OpenCL-CTS/build/test_conformance/math_brute_force$ ./test_bruteforce -w rint"

clang: CommandLine Error: Option 'h' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options
Aborted (core dumped)

Chance of failure is about 5-10%.

Researched little bit and found this is related to the problem the recently accepted LLVM patch addresses.

https://reviews.llvm.org/D129129

This fix however, is for the current version of LLVM. This might need to be rebased for LLVM12.