[binutils-gdb] [AArch64] Call abort() consistently in unhandled stub switch statements.

[sergiodj+buildbot@redhat.com]

*** TEST RESULTS FOR COMMIT 8e2fe09f70e721bfd8aaa0690537640a44538f25 ***

Author: Marcus Shawcroft <marcus.shawcroft@arm.com>
Branch: master
Commit: 8e2fe09f70e721bfd8aaa0690537640a44538f25

[AArch64] Call abort() consistently in unhandled stub switch statements.
Ensure we hard stop via abort() for unhandled stub types rather than
continuing either silently (or noisly with a BFD_FAIL()).

Call abort() giving a hard stop rather than BFD_FAIL () for unhandled
stub types.