NFC: Expunge 'actor class' in comments

include/swift/AST/ActorIsolation.h

@@ -40,7 +40,7 @@ public:
     /// The actor isolation has not been specified. It is assumed to be
     /// unsafe to interact with this declaration from any actor.
     Unspecified = 0,
-    /// The declaration is isolated to the instance of an actor class.
+    /// The declaration is isolated to the instance of an actor.
     /// For example, a mutable stored property or synchronous function within
     /// the actor is isolated to the instance of that actor.
     ActorInstance,

lib/Frontend/ModuleInterfaceSupport.cpp

@@ -521,7 +521,7 @@ public:
     if (!printOptions.shouldPrint(nominal))
       return;
 
-    /// is this nominal specifically an 'actor class'?
+    /// is this nominal specifically an 'actor'?
     bool actorClass = false;
     if (auto klass = dyn_cast<ClassDecl>(nominal))
       actorClass = klass->isActor();

lib/IRGen/GenType.cpp

@@ -2095,7 +2095,7 @@ const TypeInfo *TypeConverter::convertType(CanType ty) {
   }
   case TypeKind::BuiltinDefaultActorStorage: {
     // Builtin.DefaultActorStorage represents the extra storage
-    // (beyond the heap header) of a default actor class.  It is
+    // (beyond the heap header) of a default actor.  It is
     // fixed-size and totally opaque.
     auto numWords = NumWords_DefaultActor;
 

lib/Sema/TypeCheckConcurrency.cpp

@@ -290,18 +290,18 @@ bool IsActorRequest::evaluate(
 
 bool IsDefaultActorRequest::evaluate(
     Evaluator &evaluator, ClassDecl *classDecl) const {
-  // If the class isn't an actor class, it's not a default actor.
+  // If the class isn't an actor, it's not a default actor.
   if (!classDecl->isActor())
     return false;
 
-  // If there is a superclass, and it's an actor class, we defer
+  // If there is a superclass, and it's an actor, we defer
   // the decision to it.
   if (auto superclassDecl = classDecl->getSuperclassDecl()) {
     // If the superclass is an actor, we inherit its default-actor-ness.
     if (superclassDecl->isActor())
       return superclassDecl->isDefaultActor();
 
-    // If the superclass is not an actor class, it can only be
+    // If the superclass is not an actor, it can only be
     // a default actor if it's NSObject.  (For now, other classes simply
     // can't be actors at all.)  We don't need to diagnose this; we
     // should've done that already in isActor().
@@ -522,7 +522,7 @@ GlobalActorAttributeRequest::evaluate(
     // Nominal types are okay...
     if (auto classDecl = dyn_cast<ClassDecl>(nominal)){
       if (classDecl->isActor()) {
-        // ... except for actor classes.
+        // ... except for actors.
         nominal->diagnose(diag::global_actor_on_actor_class, nominal->getName())
             .highlight(globalActorAttr->getRangeWithAt());
         return None;

lib/Sema/TypeCheckConcurrency.h

@@ -132,7 +132,7 @@ public:
     return data.actorType;
   }
 
-  /// Retrieve the actor class that the declaration is within.
+  /// Retrieve the actor that the declaration is within.
   Type getGlobalActor() const {
     assert(kind == GlobalActor || kind == GlobalActorUnsafe);
     return Type(data.globalActor);

lib/Sema/TypeCheckStorage.cpp

@@ -118,7 +118,7 @@ static void computeLoweredStoredProperties(NominalTypeDecl *decl) {
     }
   }
 
-  // If this is an actor class, check conformance to the Actor protocol to
+  // If this is an actor, check conformance to the Actor protocol to
   // ensure that the actor storage will get created (if needed).
   if (auto classDecl = dyn_cast<ClassDecl>(decl)) {
     if (classDecl->isActor()) {

stdlib/public/Concurrency/Actor.swift

@@ -13,7 +13,7 @@
 import Swift
 @_implementationOnly import _SwiftConcurrencyShims
 
-/// Common protocol to which all actor classes conform.
+/// Common protocol to which all actors conform.
 ///
 /// The \c Actor protocol generalizes over all actor types. Actor types
 /// implicitly conform to this protocol.

unittests/runtime/Actor.cpp

@@ -85,7 +85,7 @@ static void run(llvm::function_ref<void()> fn) {
 
 namespace {
 
-/// A simple actor class.
+/// A simple actor.
 class TestActor : public DefaultActor {
 public:
   TestActor();