GLSL: Fix #1359: don't allow unsized arrays as initializers.

Test/array.frag

@@ -102,11 +102,12 @@ void foo3()
 }
 
 int[] i = int[]();    // ERROR, need constructor arguments
-float emptyA[];
-float b = vec4(emptyA);    // ERROR, array can't be a constructor argument
-uniform sampler2D s2d[];
-
-void foo4()
-{
-    s2d[a];           // ERROR, can't variably index unsized array
-}
+float emptyA[];
+float b = vec4(emptyA);    // ERROR, array can't be a constructor argument
+uniform sampler2D s2d[];
+
+void foo4()
+{
+    s2d[a];                         // ERROR, can't variably index unsized array
+    float local[] = gUnusedUnsized; // ERROR, can initialize with runtime-sized array
+}