Switch up @objc enum printing

Now that all the raw values are computed up front, change the printer to
instead require the expression not be implicit.  Previously, a NULL
element would appear instead.

Author: CodaFi

lib/PrintAsObjC/DeclAndTypePrinter.cpp

@@ -393,13 +393,12 @@ class DeclAndTypePrinter::Implementation
         os << " SWIFT_COMPILE_NAME(\"" << Elt->getName() << "\")";
       }
 
-      auto *RVE = Elt->getStructuralRawValueExpr();
-      if (auto ILE = cast_or_null<IntegerLiteralExpr>(RVE)) {
-        os << " = ";
-        if (ILE->isNegative())
-          os << "-";
-        os << ILE->getDigitsText();
-      }
+      // Print the raw values, even the ones that we synthesize.
+      auto *ILE = cast<IntegerLiteralExpr>(Elt->getStructuralRawValueExpr());
+      os << " = ";
+      if (ILE->isNegative())
+        os << "-";
+      os << ILE->getDigitsText();
       os << ",\n";
     }
     os << "};\n";