[aarch64][libstdc++] Use __ARM_BIG_ENDIAN instead of __AARCH64EB__ in opt_random.h
As has been spotted at https://gcc.gnu.org/ml/gcc-patches/2017-12/msg01289.html
we check the __AARCH64EB__ macro for aarch64 big-endian
detection in config/cpu/aarch64/opt/ext/opt_random.h.
That works just fine with GCC but the standardised ACLE[1] macro
for that purpose is __ARM_BIG_ENDIAN so there is a possibility
that non-GCC compilers that include this header are not aware
of this predefine.
So this patch changes the use of __AARCH64EB__ to
the more portable __ARM_BIG_ENDIAN.
Tested on aarch64-none-elf and aarch64_be-none-elf.
Preapproved by Jeff at https://gcc.gnu.org/ml/gcc-patches/2017-12/msg01326.html
* config/cpu/aarch64/opt/ext/opt_random.h (__VEXT): Check
__ARM_BIG_ENDIAN instead of __AARCH64EB__.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@255857 138bc75d-0d04-0410-961f-82ee72b054a4