Get all the scoping rules right for ES and non ES, name hiding, built-in overriding, etc.

git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@21948 e7fa87d3-cd2b-0410-9028-fcbf551c1848

Test/430scope.vert

@@ -0,0 +1,64 @@
+#version 430 core
+
+int f(int a, int b, int c)
+{
+	int a = b;  // ERROR, redefinition
+
+    {
+		float a = float(a) + 1.0; // okay
+    }
+
+	return a;
+}
+
+int f(int a, int b, int c);  // okay to redeclare
+
+bool b;
+float b(int a);      // ERROR: redefinition
+
+float f;             // ERROR: redefinition
+float tan;           // okay, hides built-in function
+float sin(float x);  // okay, can overload built-in functions
+float cos(float x)   // okay, can overload built-in functions
+{
+	return 1.0;
+}
+
+invariant gl_Position;
+
+void main()
+{
+    int g();    // okay
+    g();
+
+    float sin; // okay
+    sin;
+
+    f(1,2,3);
+
+    float f;    // hides f()
+    f = 3.0;
+
+    gl_Position = vec4(f);
+
+    for (int f = 0; f < 10; ++f)
+        ++f;
+
+    int x = 1;
+    { 
+        float x = 2.0, /* 2nd x visible here */ y = x; // y is initialized to 2
+        int z = z; // ERROR: z not previously defined.
+    }
+    {
+        int x = x; // x is initialized to '1'
+    }
+
+    struct S 
+    { 
+        int x; 
+    };
+    {
+        S S = S(0); // 'S' is only visible as a struct and constructor 
+        S.x;        // 'S' is now visible as a variable
+    }
+}