Hi,

Currently patchable area is at the wrong place on AArch64.  It is placed
immediately after function label, before .cfi_startproc.  This patch
adds UNSPECV_PATCHABLE_AREA for pseudo patchable area instruction and
modifies aarch64_print_patchable_function_entry to avoid placing
patchable area before .cfi_startproc.

The patch passed bootstrap and regression test on aarch64-linux.
Ok to commit to trunk and backport to active release branches?

Thanks,
Sebastian

gcc/
        PR target/93492
        * config/aarch64/aarch64-protos.h (aarch64_output_patchable_area):
        Declared.
        * config/aarch64/aarch64.cc (aarch64_print_patchable_function_entry):
        Emit an UNSPECV_PATCHABLE_AREA pseudo instruction.
        (aarch64_output_patchable_area): New.
        * config/aarch64/aarch64.md (UNSPECV_PATCHABLE_AREA): New.
        (patchable_area): Define.

gcc/testsuite/
        PR target/93492
        * gcc.target/aarch64/pr98776.c: New.