Optimize prologue/epilogue instructions if a given function use GOT but
do not call other functions by eliminating FP. Previously, we had wrong
implementations taken from other architectures. Update regression tests
also.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D92313
Optimize address calculations using LEA/LEASL instructions.
Update comments in VEISelLowering.cpp also. Update an
existing regression test optimized by this modification.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D90878