re PR c/81795 (Stray "originally defined here" when using -Wc++-compat with #pragma GCC diagnostic push/pop)

	PR c/81795
	* c-decl.c (pushtag): Only print inform if the warning was printed.
	(grokdeclarator): Likewise.

	* gcc.dg/pr81795.c: New test.

From-SVN: r251056