[svn r104] TONS OF FIXES.

Split up declaration, constant initializer gen and definition for globals, structs, classes and functions.
Improved ClassInfo support (not complete), not in vtable yet.
Fixed a bunch of forward reference problems.
Much more. Major commit! :)

test/structs7.d

@@ -0,0 +1,15 @@
+module structs7;
+
+pragma(LLVM_internal, "notypeinfo")
+struct S
+{
+    int i;
+    long l;
+}
+
+void main()
+{
+    S s = void;
+    int i = s.i;
+    long l = s.l;
+}