update documentation

Author: samjwu

amd/hipcc/docs/env.md

@@ -7,6 +7,5 @@ The environment variable HIP_PLATFORM may be used to specify amd/nvidia:
 Other environment variable controls:
 - HIP_PATH        : Path to HIP directory, default is one dir level above location of hipcc.
 - CUDA_PATH       : Path to CUDA SDK (default /usr/local/cuda). Used on NVIDIA platforms only.
-- HSA_PATH        : Path to HSA dir (defaults to ../../hsa relative to abs_path of hipcc). Used on AMD platforms only.
 - HIP_ROCCLR_HOME : Path to HIP/ROCclr directory. Used on AMD platforms only.
 - HIP_CLANG_PATH  : Path to HIP-Clang (default to ../../llvm/bin relative to hipcc's abs_path). Used on AMD platforms only.

amd/hipcc/docs/index.md

@@ -1,5 +1,5 @@
 # HIPCC
 
-`hipcc` is a compiler driver utility that will call clang or nvcc, depending on target, and pass the appropriate include and library options for the target compiler and HIP infrastructure. Historically, `hipcc` was provided as a script in the HIP repo ( https://github.com/ROCm-Developer-Tools/HIP/blob/main/bin/hipcc ). The `hipcc` provided in this project provides the same functionality, but is a binary rather than a script. At some point in the future, the hipcc script will be deprecated and ultimately removed from the HIP repo.
+`hipcc` is a compiler driver utility that will call clang or nvcc, depending on target, and pass the appropriate include and library options for the target compiler and HIP infrastructure. 
 
-`hipcc` will pass-through options to the target compiler. The tools calling hipcc must ensure the compiler options are appropriate for the target compiler.
+There is both a Perl version, and a C++ executable version of the hipcc/hipconfig compiler driver utilities provided. Currently, by default the Perl version is used when 'hipcc' is called. To enable the C++ executable versions, set the environment variable `HIP_USE_PERL_SCRIPTS=0`.