AArch64: Update system register database.

AArch64: Update system register database.

With the release of Binutils 2.42, this brings the level of
system-register support in GCC in line with the current
state-of-the-art in Binutils, ensuring everything available in
Binutils is plainly accessible from GCC.

Where Binutils uses a more detailed description of which features are
responsible for enabling a given system register, GCC aliases the
binutils-equivalent feature flag macro constant to that of the base
architecture implementing the feature, resulting in entries such as

  #define AARCH64_FL_S2PIE	   AARCH64_FL_V8_9A

in `aarch64.h', thus ensuring that the Binutils `aarch64-sys-regs.def'
file can be understood by GCC without the need for modification.

To accompany the addition of the new system registers, a new test is
added confirming they were successfully added to the list of
recognized registers.

gcc/ChangeLog:

	* config/aarch64/aarch64-sys-regs.def: Copy from Binutils.
	* config/aarch64/aarch64.h (AARCH64_FL_AIE): New.
	(AARCH64_FL_DEBUGv8p9): Likewise.
	(AARCH64_FL_FGT2): Likewise.Likewise.
	(AARCH64_FL_ITE): Likewise.
	(AARCH64_FL_PFAR): Likewise.
	(AARCH64_FL_PMUv3_ICNTR): Likewise.
	(AARCH64_FL_PMUv3_SS): Likewise.
	(AARCH64_FL_PMUv3p9): Likewise.
	(AARCH64_FL_RASv2): Likewise.
	(AARCH64_FL_S1PIE): Likewise.
	(AARCH64_FL_S1POE): Likewise.
	(AARCH64_FL_S2PIE): Likewise.
	(AARCH64_FL_S2POE): Likewise.
	(AARCH64_FL_SCTLR2): Likewise.
	(AARCH64_FL_SEBEP): Likewise.
	(AARCH64_FL_SPE_FDS): Likewise.
	(AARCH64_FL_TCR2): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/acle/rwsr-armv8p9.c: New.