This patch implements the builtins for cmplxl by utilising
__builtin_complex. This builtin is implemented to match XL
functionality.
Differential revision: https://reviews.llvm.org/D107138
Added a number of different builtins that exist in the XL compiler. Most of
these builtins already exist in clang under a different name.
Reviewed By: nemanjai, #powerpc
Differential Revision: https://reviews.llvm.org/D104386