Utilize common API in PPCTargetParser
(https://github.com/llvm/llvm-project/pull/97541) to set default CPU
with same interfaces for LLC.
This will update AIX default CPU to pwr7 and LoP powerppc64 default CPU
to ppc64.
Summary: Currently, if there are multiple definitions of the same symbol declared has weak linkage, the linker may choose the wrong one when they are compiled with integrated-as. This patch fixes the issue. If the target symbol is a weak label we must not attempt to resolve the fixup directly. Emit a relocation and leave resolution of the final target address to the linker.
Reviewed By: shchenz
Differential Revision: https://reviews.llvm.org/D153839
