glcpp: Support #if(expression) with no intervening space.

And add a test case to ensure that this works.

src/glsl/glcpp/glcpp-lex.l

@@ -99,7 +99,7 @@ HEXADECIMAL_INTEGER	0[xX][0-9a-fA-F]+[uU]?
 	return HASH_IFNDEF;
 }
 
-{HASH}if{HSPACE}/.*\n {
+{HASH}if{HSPACE}*/[^_a-zA-Z0-9].*\n {
 	yyextra->lexing_if = 1;
 	yyextra->space_tokens = 0;
 	return HASH_IF;

src/glsl/glcpp/tests/066-if-nospace-expression.c

@@ -0,0 +1,3 @@
+#if(1)
+success
+#endif

src/glsl/glcpp/tests/066-if-nospace-expression.c.expected

@@ -0,0 +1,4 @@
+
+success
+
+