[PATCH][ARM][PR target/78945] Fix libatomic on armv7-m

[Szabolcs Nagy]

On 25/01/17 12:35, Szabolcs Nagy wrote:
> ARM libatomic inline asm uses sel, uadd8, uadd16 instructions
> which are only available if __ARM_FEATURE_SIMD32 is defined.
> 
> libatomic/
> 2017-01-25  Szabolcs Nagy  <szabolcs.nagy@arm.com>
> 
> 	PR target/78945
> 	* config/arm/exch_n.c (libat_exchange): Check __ARM_FEATURE_SIMD32.

committed based on
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78945#c2

i will backport it to release branches.