* cpp.texi: Update for new command line assertion syntax.
	* cpplib.c (cpp_define): Simplify a bit.
	(cpp_assert, cpp_unassert): Use handle_assertion.
	(handle_assertion): New function; accept new command line
	syntax with '='.
	* testsuite/gcc.dg/cpp/assert3.c: New tests.

From-SVN: r37171