Non-functional. Rationalizations enabling future generalizations:

- Use much simpler method to update implicit array sizes.
  The previous overly complicated method was error prone.
- Rationalize all use of unsized arrays.
- Combine decorations when generating SPIR-V, to simplify
  adding extensions.

Test/array.frag

@@ -104,3 +104,9 @@ 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
+}