[SYCL][E2E] Stop CMAKE_CXX_FLAGS cache variable passing to clang++#20039

sarnex merged 3 commits intointel:syclintel/llvm:syclfrom

Maetveis:dont_pass_cmake_cxx_flags_cache_to_sycl_e2eMaetveis/llvm:dont_pass_cmake_cxx_flags_cache_to_sycl_e2eCopy head branch name to clipboard