When UBSan is enabled, I noticed runtime errors complaining of shifting
of negative numbers.
This patch fixes this by reusing existing macros from the ARM port.
It also removes unused macros from AArch64's port.
gdb/ChangeLog:
2020-12-04 Luis Machado <luis.machado@linaro.org>
* aarch64-tdep.c (submask, bit, bits): Remove.
* arch/aarch64-insn.c (extract_signed_bitfield): Remove.
(aarch64_decode_adr, aarch64_decode_b aarch64_decode_bcond)
(aarch64_decode_cb, aarch64_decode_tb)
(aarch64_decode_ldr_literal): Use sbits to extract a signed
immediate.
* arch/aarch64-insn.h (submask, bits, bit, sbits): New macros.
5382f97180