[PATCH][GCC] aarch64: Add +flagm to -march

[Przemyslaw Wirkus via Gcc-patches]

New +flagm (Condition flag manipulation from Armv8.4-A) feature option for
-march command line option.

Please note that FLAGM stays an Armv8.4-A feature but now can be
assigned to other architectures or CPUs.

OK for master?

gcc/ChangeLog:

        * config/aarch64/aarch64-option-extensions.def
        (AARCH64_OPT_EXTENSION): New +flagm option in -march for AArch64.
        * config/aarch64/aarch64.h (AARCH64_FL_FLAGM): Add new flagm extension 
bit
        mask.
        (AARCH64_FL_FOR_ARCH8_4): Add flagm to Armv8.4-A.

rb13807.patch
Description: rb13807.patch