* cppexp.c (ALWAYS_EVAL): Remove.

	(optab, reduce): Always evaluate.
	(num_unary_op, num_binary_op, num_div_op): Issue diagnostics
	only if not skipping evaluation.
testsuite:
	* gcc.dg/cpp/expr.c: New tests.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@55595 138bc75d-0d04-0410-961f-82ee72b054a4