[ParseableInterfaces] Print Builtin. before builtin types

This is only relevant to the standard library, but previously we would not print `Builtin.` before builtin types. Make sure we do.

Author: Harlan Haskins

lib/AST/ASTPrinter.cpp

@@ -3512,6 +3512,8 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
     if (auto parent = T->getParent()) {
       visit(parent);
       Printer << ".";
+    } else if (shouldPrintFullyQualified(T)) {
+      printModuleContext(T);
     }
 
     printTypeDeclName(T);