[backport gcc-10][AArch64] ACLE bf16 get

[Dennis Zhang]

Hi all,

This patch backports the commit 3553c658533e430b232997bdfd97faf6606fb102.
The original is approved at https://gcc.gnu.org/pipermail/gcc-patches/2020-November/557871.html
There is a change to remove FPCR-reading flag for builtin declaration since it's not supported in gcc-10.

Another change is to remove a test (bf16_get-be.c) that fails compiling on aarch64-none-linux-gnu in the original patch.
This is reported at https://gcc.gnu.org/pipermail/gcc-patches/2020-November/558195.html
The failure happens for several bf16 big-endian tests so the bug would be fixed in a separate patch.
And the test should be added after the bug is fixed.

Is it OK to backport?

Cheers
Dennis
-------------- next part --------------
A non-text attachment was scrubbed...
Name: rb13903.patch
Type: text/x-patch
Size: 3748 bytes
Desc: rb13903.patch
URL: <https://gcc.gnu.org/pipermail/gcc-patches/attachments/20201210/2eec1f95/attachment.bin>