This patch adds tests for the code generated by the Aarch64 backend for the
__sync builtins.

Tested aarch64-none-linux-gnu with check-gcc.

Ok for trunk?
Matthew

gcc/testsuite/
2015-05-21  Matthew Wahab  <matthew.wahab@arm.com>

	* gcc.target/aarch64/sync-comp-swap.c: New.
	* gcc.target/aarch64/sync-comp-swap.x: New.
	* gcc.target/aarch64/sync-op-acquire.c: New.
	* gcc.target/aarch64/sync-op-acquire.x: New.
	* gcc.target/aarch64/sync-op-full.c: New.
	* gcc.target/aarch64/sync-op-full.x: New.
	* gcc.target/aarch64/sync-op-release.c: New.
	* gcc.target/aarch64/sync-op-release.x: New.