[Type Checker] Check subpattern storage instead of whole pattern.

Fixes SR-1050, where @NSManaged subpatterns were not yet visited, and
thus still were deemed 'stored', by the time getStorage() was called
on the whole pattern. Change this to check the subpattern storage as
we go. Test case added.

Author: milseman

include/swift/AST/Pattern.h

@@ -166,6 +166,9 @@ class alignas(8) Pattern {
     });
   }
 
+  /// Does this binding declare something that requires storage?
+  bool hasStorage() const;
+
   static bool classof(const Pattern *P) { return true; }
 
   //*** Allocation Routines ************************************************/

lib/AST/Decl.cpp

@@ -991,14 +991,10 @@ StaticSpellingKind PatternBindingDecl::getCorrectStaticSpelling() const {
 bool PatternBindingDecl::hasStorage() const {
   // Walk the pattern, to check to see if any of the VarDecls included in it
   // have storage.
-  bool HasStorage = false;
   for (auto entry : getPatternList())
-    entry.getPattern()->forEachVariable([&](VarDecl *VD) {
-      if (VD->hasStorage())
-        HasStorage = true;
-    });
-
-  return HasStorage;
+    if (entry.getPattern()->hasStorage())
+      return true;
+  return false;
 }
 
 void PatternBindingDecl::setPattern(unsigned i, Pattern *P) {

lib/AST/Pattern.cpp

@@ -237,6 +237,16 @@ void Pattern::forEachNode(const std::function<void(Pattern*)> &f) {
   }
 }
 
+bool Pattern::hasStorage() const {
+  bool HasStorage = false;
+  forEachVariable([&](VarDecl *VD) {
+    if (VD->hasStorage())
+      HasStorage = true;
+  });
+
+  return HasStorage;
+}
+
 /// Return true if this is a non-resolved ExprPattern which is syntactically
 /// irrefutable.
 static bool isIrrefutableExprPattern(const ExprPattern *EP) {

lib/Sema/TypeCheckDecl.cpp

@@ -3245,7 +3245,7 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
         // default-initializable. If so, do it.
         if (PBD->getPattern(i)->hasType() &&
             !PBD->getInit(i) &&
-            PBD->hasStorage() &&
+            PBD->getPattern(i)->hasStorage() &&
             !PBD->getPattern(i)->getType()->is<ErrorType>()) {
 
           // If we have a type-adjusting attribute (like ownership), apply it now.

test/decl/var/NSManaged_properties.swift

@@ -48,6 +48,9 @@ class SwiftGizmo : A {
   @NSManaged func mutableArrayValueForB() {} // expected-error {{NSManaged method cannot have a body; it must be provided at runtime}}
   @NSManaged class func mutableArrayValueForA() {} // expected-error {{@NSManaged only allowed on an instance property or method}}
 
+  // SR-1050: don't assert
+  @NSManaged var multiA, multiB, multiC : NSNumber?
+
   override init() {}
 }