[Type checker] Only "use" bridging conformances when there is a type checker.

Works around rdar://problem/45047761 and rdar://problem/45058722.

Author: DougGregor

lib/Sema/TypeCheckDeclObjC.cpp

@@ -1539,8 +1539,11 @@ void markAsObjC(ValueDecl *D, ObjCReason reason,
   }
 
   if (!isa<TypeDecl>(D) && !isa<AccessorDecl>(D) && !isa<EnumElementDecl>(D)) {
-    useObjectiveCBridgeableConformances(D->getInnermostDeclContext(),
-                                        D->getInterfaceType());
+    if (ctx.getLazyResolver()) {
+      // Only record conformances when we have a lazy resolver.
+      useObjectiveCBridgeableConformances(D->getInnermostDeclContext(),
+                                          D->getInterfaceType());
+    }
   }
 
   if (auto method = dyn_cast<AbstractFunctionDecl>(D)) {

validation-test/compiler_crashers_2_fixed/0178-rdar-45060773.swift

@@ -0,0 +1,7 @@
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -c -primary-file %s %S/Inputs/0178-rdar-45060773-other.swift -o /dev/null
+
+// REQUIRES: objc_interop
+
+func doit() {
+  MyCls().something(true)
+}

validation-test/compiler_crashers_2_fixed/Inputs/0178-rdar-45060773-other.swift

@@ -0,0 +1,8 @@
+import Foundation
+
+class MyCls: NSObject {
+}
+
+extension MyCls {
+  @objc func something(_: Bool) {}
+}