Fix the AccessStrategy for dynamic (not @objc) storage

It needs to be opaque but not dispatched.

Author: aschwaighofer

lib/AST/Decl.cpp

@@ -1416,7 +1416,7 @@ SourceRange IfConfigDecl::getSourceRange() const {
 }
 
 static bool isPolymorphic(const AbstractStorageDecl *storage) {
-  if (storage->isDynamic())
+  if (storage->isObjCDynamic())
     return true;
 
 
@@ -1623,6 +1623,9 @@ AbstractStorageDecl::getAccessStrategy(AccessSemantics semantics,
       if (isPolymorphic(this))
         return getOpaqueAccessStrategy(this, accessKind, /*dispatch*/ true);
 
+      if (isDynamic())
+        return getOpaqueAccessStrategy(this, accessKind, /*dispatch*/ false);
+
       // If the storage is resilient to the given use DC (perhaps because
       // it's @_transparent and we have to be careful about it being inlined
       // across module lines), we cannot use direct access.

test/SILGen/keypath_dynamic.swift

@@ -0,0 +1,19 @@
+// RUN: %target-swift-emit-silgen -enable-sil-ownership -module-name A %s | %FileCheck %s
+
+struct Foo {
+  var x : Int {
+    get {
+      return 1
+    }
+    set {
+    }
+  }
+
+  func foo(_ kp: WritableKeyPath<Foo, Int>) {
+  }
+
+  func test() {
+    // CHECK: keypath $WritableKeyPath<Foo, Int>, (root $Foo; settable_property $Int,  id @$s1A3FooV1xSivg
+    foo(\.x)
+  }
+}