Linux clang toolchain targets

Is it too late to include "x86_64-unknown-linux" as a supported toolchain name in clang? We tend to need to hand-patch clang source to find include files properly on our systems, the patch looks something like this (just posting as a guideline, I'm not sure if this is the best approach or not, but it seems to work for us):

Index: lib/Frontend/InitHeaderSearch.cpp