[Parse] [Sema] Ensure lazy immediate mode only enabled when requested

Author: Zak Kent

lib/Frontend/Frontend.cpp

@@ -1576,7 +1576,9 @@ CompilerInstance::getSourceFileParsingOptions(bool forPrimary) const {
       frontendOpts.ReuseFrontendForMultipleCompilations) {
     opts |= ParsingFlags::EnableInterfaceHash;
   }
-  if (action == ActionType::Immediate) {
+  const auto &LangOpts = Invocation.getLangOptions();
+  if (action == ActionType::Immediate &&
+      LangOpts.hasFeature(Feature::LazyImmediate)) {
     opts -= ParsingFlags::DisableDelayedBodies;
     opts -= ParsingFlags::ValidateNewParserDiagnostics;
   }

lib/Sema/TypeChecker.cpp

@@ -306,7 +306,8 @@ TypeCheckSourceFileRequest::evaluate(Evaluator &eval, SourceFile *SF) const {
         }
       }
     }
-    if (!Ctx.TypeCheckerOpts.DeferToRuntime) {
+    if (!Ctx.TypeCheckerOpts.DeferToRuntime ||
+        !Ctx.LangOpts.hasFeature(Feature::LazyImmediate)) {
       typeCheckDelayedFunctions(*SF);
     }
   }