When building on x86_64 with -DCOMPILER_RT_USE_BUILTINS_LIBRARY=ON we try to build sanitizers for both x86_64 and i386 but we tried to link both to the x86_64 builtins.
This patch uses the correct builtins to link into the sanitizers.
Based on patch attached here: https://bugs.llvm.org/show_bug.cgi?id=38025