[Linux, Mac] Prism build script unnecessary mixing of 2 different compilers

This mixing of compilers can be a source of problem in the future and it is preventing Parfait build for Prism

def compiler = IS_COMPILE_PARFAIT ? "parfait-gcc" : "gcc";
def cc_compiler = IS_COMPILE_PARFAIT ? "parfait-cc" : "cc";
def linker = IS_COMPILE_PARFAIT ? "parfait-g++" : "g++";