openmp: Reject invalid forms of C++ #pragma omp atomic compare [PR106448]

openmp: Reject invalid forms of C++ #pragma omp atomic compare [PR106448]

The allowed syntaxes of atomic compare don't allow ()s around the condition
of ?:, but we were accepting it in one case for C++.

Fixed thusly.

2022-07-29  Jakub Jelinek  <jakub@redhat.com>

	PR c++/106448
	* parser.cc (cp_parser_omp_atomic): For simple cast followed by
	CPP_QUERY token, don't try cp_parser_binary_operation if compare
	is true.

	* c-c++-common/gomp/atomic-32.c: New test.