[ASTScope] Always skip implicit attributes.

ASTScope only cares about attributes when lookup can be done inside of the
attribute, which isn't the case for implicit attributes because they're
typically built fully type-checked. This also avoids a crash when an
implicit attribute does not have a source range.

Author: hborla

lib/AST/ASTScopeCreation.cpp

@@ -506,10 +506,11 @@ void ScopeCreator::addChildrenForKnownAttributes(ValueDecl *decl,
   SmallVector<DeclAttribute *, 2> relevantAttrs;
 
   for (auto *attr : decl->getAttrs()) {
-    if (isa<DifferentiableAttr>(attr)) {
-      if (!attr->isImplicit())
-        relevantAttrs.push_back(attr);
-    }
+    if (attr->isImplicit())
+      continue;
+
+    if (isa<DifferentiableAttr>(attr))
+      relevantAttrs.push_back(attr);
 
     if (isa<SpecializeAttr>(attr))
       relevantAttrs.push_back(attr);

test/Concurrency/global_actor_inference.swift

@@ -282,6 +282,17 @@ struct WrapperOnActor<Wrapped> {
   }
 }
 
+@MainActor
+@propertyWrapper
+public struct WrapperOnMainActor<Wrapped> {
+  // Make sure inference of @MainActor on wrappedValue doesn't crash.
+  public var wrappedValue: Wrapped
+
+  public init(wrappedValue: Wrapped) {
+    self.wrappedValue = wrappedValue
+  }
+}
+
 @propertyWrapper
 actor WrapperActor<Wrapped> {
   @actorIndependent(unsafe) var storage: Wrapped