testsuite: Require atomic operations for pr47333_0

testsuite: Require atomic operations for pr47333_0

Since the test uses __sync_fetch_and_add, add a requirement for
target to support atomic operations on int and long types.

This fixes a spurious test failure on pru-unknown-elf, which lacks
atomic ops. The test still passes on x86_64-linux-gnu.

gcc/testsuite/ChangeLog:

	* g++.dg/lto/pr47333_0.C: Require target that supports atomic
	operations on int and long types.

Signed-off-by: Dimitar Dimitrov <dimitar@dinux.eu>