On Gentoo, ROCM_PATH=/usr we do not need to set -I${ROCM_PATH}/include.
Actually it is harmful to the `include_next`s.

Index: ROCm-CompilerSupport-rocm-4.3.0/lib/comgr/src/comgr-compiler.cpp
===================================================================
--- comgr/src/comgr-compiler.cpp
+++ comgr/src/comgr-compiler.cpp
@@ -927,8 +927,6 @@ AMDGPUCompiler::addTargetIdentifierFlags
 
 amd_comgr_status_t AMDGPUCompiler::addCompilationFlags() {
   HIPIncludePath = (Twine(env::getHIPPath()) + "/include").str();
-  // HIP headers depend on hsa.h which is in ROCM_DIR/include.
-  ROCMIncludePath = (Twine(env::getROCMPath()) + "/include").str();
   ClangIncludePath =
       (Twine(env::getLLVMPath()) + "/lib/clang/" + CLANG_VERSION_STRING).str();
   ClangIncludePath2 = (Twine(env::getLLVMPath()) + "/lib/clang/" +