glsl/glcpp: Add explicit error for "#define without macro name"

Previously, glcpp would emit an error like this if <EOF> happened to occur
immediately after the "#define", but in general would just get confused,
(leading to un-helpful error messages).

To fix things to generate a clean error message, we do a few things:

	1. Don't require horizontal whitespace immediately after #define

	2. Add a production for the error case, (DEFINE_TOKEN followed
	   immediately by a NEWLINE token).

	3. Make the lexer reset to the <INITIAL> state after every NEWLINE.

This 3rd point prevents the lexer from getting so confused and generating
further spurious errors in the file because it was stuck in the <DEFINE> start
condition.

We also drop the similar error message from the <EOF> rule since the
newly-added rule will have already printed the error message.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/glsl/glcpp/glcpp-parse.y

@@ -424,6 +424,9 @@ control_line_error:
 	HASH_TOKEN ERROR_TOKEN NEWLINE {
 		glcpp_error(& @1, parser, "#%s", $2);
 	}
+|	HASH_TOKEN DEFINE_TOKEN NEWLINE {
+		glcpp_error (& @1, parser, "#define without macro name");
+	}
 |	HASH_TOKEN GARBAGE pp_tokens NEWLINE  {
 		glcpp_error (& @1, parser, "Illegal non-directive after #");
 	}