Add amend ability for anonymous blocks, so they can grow between function bodies.

Test/hlsl.amend.frag

@@ -0,0 +1,28 @@
+float4 a;
+float b;
+
+void f1()
+{
+    a * b;
+}
+
+float3 c;
+
+void f2()
+{
+    a.x + b + c.x;
+}
+
+void f3()
+{
+    c;
+}
+
+int d;
+
+void f4()
+{
+    d * a;
+}
+
+int e;