[AArch64] Use gen_frame_mem for callee-saves
The frame code uses a mixture of gen_rtx_MEM and gen_frame_mem for
callee-saves. Callee-saves never alias with local variables, so using
gen_frame_mem is best.
gcc/
* config/aarch64/aarch64.c (aarch64_pushwb_single_reg):
Use gen_frame_mem.
(aarch64_pop_regs): Likewise.
(aarch64_gen_load_pair): Likewise.
(aarch64_save_callee_saves): Likewise.
(aarch64_restore_callee_saves): Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@250919 138bc75d-0d04-0410-961f-82ee72b054a4