More subtle checking for redeclarations:

- 300 doesn't allow built-in overload, while 100 does, while neither allows redefining
 - block name can't be reused for block name within the same interface 
   (though, the spec. isn't clear about that, it's easier than verifying member matches, will file bug on it)


git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@23984 e7fa87d3-cd2b-0410-9028-fcbf551c1848

Test/300scope.vert

@@ -18,11 +18,15 @@ float b(int a);      // ERROR: redefinition
 
 float f;             // ERROR: redefinition
 float tan;           // ERROR: redefines built-in function
-float sin(float x);  // ERROR: can't overload built-in functions
-float cos(float x)   // ERROR: can't overload built-in functions
+float sin(float x);  // ERROR: can't redefine built-in functions
+float cos(float x)   // ERROR: can't redefine built-in functions
 {
 	return 1.0;
 }
+bool radians(bool x) // ERROR: can't overload built-in functions
+{
+    return true;
+}
 
 invariant gl_Position;