Outliner: Verify that getBridgeFromObjectiveC and getBridgeToObjectiveC return a valid SILDeclRef (#28703)

rdar://57757241

lib/SILOptimizer/Transforms/Outliner.cpp

@@ -492,7 +492,8 @@ static bool matchSwitch(SwitchInfo &SI, SILInstruction *Inst,
   auto *BridgeFun = FunRef->getInitiallyReferencedFunction();
   auto *SwiftModule = BridgeFun->getModule().getSwiftModule();
   auto bridgeWitness = getBridgeFromObjectiveC(NativeType, SwiftModule);
-  if (BridgeFun->getName() != bridgeWitness.mangle())
+  if (bridgeWitness == SILDeclRef() ||
+      BridgeFun->getName() != bridgeWitness.mangle())
     return false;
 
   // %41 = enum $Optional<String>, #Optional.some!enumelt.1, %40 : $String
@@ -809,7 +810,8 @@ BridgedArgument BridgedArgument::match(unsigned ArgIdx, SILValue Arg,
   auto *BridgeFun = FunRef->getInitiallyReferencedFunction();
   auto *SwiftModule = BridgeFun->getModule().getSwiftModule();
   auto bridgeWitness = getBridgeToObjectiveC(NativeType, SwiftModule);
-  if (BridgeFun->getName() != bridgeWitness.mangle())
+  if (bridgeWitness == SILDeclRef() ||
+      BridgeFun->getName() != bridgeWitness.mangle())
     return BridgedArgument();
 
   return BridgedArgument(ArgIdx, FunRef, BridgeCall, Enum, BridgedValueRelease,

test/SILOptimizer/Inputs/Outliner.h

@@ -34,6 +34,7 @@ typedef NS_ENUM(NSUInteger, MyEventType) {
 
 @interface MyView : NSObject
 @property (nonatomic, nullable, readonly, strong) MyWindow *window;
+@property (nonatomic, nullable, strong) MyWindow *window2;
 @end
 
 typedef struct MyPoint {

test/SILOptimizer/outliner.swift

@@ -222,3 +222,20 @@ public func testCalendar() {
    let formatter = DateFormatter()
    formatter.calendar = Calendar(identifier: .gregorian)
 }
+
+open class Test
+{
+   @inline(never)
+   public func getWindow() -> MyWindow
+   {
+       return MyWindow()
+   }
+
+   public func testDontCrash() -> MyView
+   {
+
+     let view = MyView()
+     view.window2 = getWindow()
+     return view
+   }
+}