Clang Issue Fix - Set clang as default CXX Compiler

[kiritigowda]

• Set clang as default CXX Compiler

[kiritigowda]

@rrawther

This PR fails on RedHat & SLES due to missing Clang RT location in

https://github.com/ROCm-Developer-Tools/hipamd/blob/474e8620099a463ad2ced821ae7400609b29bf7f/hip-config.cmake.in#L294

CMake Error at /opt/rocm/hip/lib/cmake/hip/hip-config.cmake:331 (message):
  clangrt builtins lib not found
Call Stack (most recent call first):
  CMakeLists.txt:181 (find_package)

On RedHat

In file /opt/rocm/hip/lib/cmake/hip/hip-config.cmake the clang_rt.builtins library is located in /usr/lib64/clang/ and not in lib-- need to add directory structure for RedHat.

file(GLOB HIP_CLANGRT_LIB_SEARCH_PATHS "${HIP_CLANG_ROOT}/lib/clang/*/lib/*")
  find_library(CLANGRT_BUILTINS
    NAMES
      clang_rt.builtins
      clang_rt.builtins-x86_64
    PATHS
      ${HIP_CLANGRT_LIB_SEARCH_PATHS}
      ${HIP_CLANG_INCLUDE_PATH}/../lib/linux
      ${HIP_CLANG_INCLUDE_PATH}/../lib/windows
      NO_DEFAULT_PATH)

• RedHat

HIP_CLANG_ROOT - /usr
HIP_CLANGRT_LIB_SEARCH_PATHS - 
HIP_CLANG_INCLUDE_PATH - HIP_CLANG_INCLUDE_PATH-NOTFOUND

• Ubuntu

HIP_CLANG_ROOT - /usr/lib/llvm-14
HIP_CLANGRT_LIB_SEARCH_PATHS - 
HIP_CLANG_INCLUDE_PATH - /usr/lib/llvm-14/lib/clang/14.0.0/include