libgccjit: Do not treat warnings as errors

libgccjit: Do not treat warnings as errors

gcc/jit/ChangeLog:

	* jit-playback.cc (add_error, add_error_va): Send DK_ERROR to
	add_error_va.
	(add_diagnostic): Call add_diagnostic instead of add_error.
	* jit-recording.cc (DEFINE_DIAGNOSTIC_KIND): New define.
	(recording::context::add_diagnostic): New function.
	(recording::context::add_error): Send DK_ERROR to add_error_va.
	(recording::context::add_error_va): New parameter diagnostic_kind.
	* jit-recording.h (add_diagnostic): New function.
	(add_error_va): New parameter diagnostic_kind.
	* libgccjit.cc (jit_error): Send DK_ERROR to add_error_va.

gcc/testsuite/ChangeLog:

	* jit.dg/test-error-array-bounds.c: Fix test.