[binutils-gdb] Make aarch64_decode_adrp handle both ADR and ADRP instructions

[sergiodj+buildbot at redhat dot com]

*** TEST RESULTS FOR COMMIT 6ec5f4be052e594dc90b6677fec1c1e7727d9651 ***

Author: Pierre Langlois <pierre.langlois@arm.com>
Branch: master
Commit: 6ec5f4be052e594dc90b6677fec1c1e7727d9651

Make aarch64_decode_adrp handle both ADR and ADRP instructions

We will need to decode both ADR and ADRP instructions in GDBserver.
This patch makes common code handle both cases, even if GDB only needs
to decode the ADRP instruction.

gdb/ChangeLog:

	* aarch64-tdep.c (aarch64_analyze_prologue): New is_adrp
	variable.  Call aarch64_decode_adr instead of
	aarch64_decode_adrp.
	* arch/aarch64-insn.h (aarch64_decode_adrp): Delete.
	(aarch64_decode_adr): New function declaration.
	* arch/aarch64-insn.c (aarch64_decode_adrp): Delete.
	(aarch64_decode_adr): New function, factored out from
	aarch64_decode_adrp to decode both adr and adrp instructions.