[AST] Rename SubscriptDecl::create -> createParsed

And generate the DeclName using the argument labels
on the ParameterList.

Author: hamishknight

include/swift/AST/Decl.h

@@ -6843,13 +6843,12 @@ class SubscriptDecl : public GenericContext, public AbstractStorageDecl {
                                            Type ElementTy, DeclContext *Parent,
                                            GenericParamList *GenericParams);
 
-  static SubscriptDecl *create(ASTContext &Context, DeclName Name,
-                               SourceLoc StaticLoc,
-                               StaticSpellingKind StaticSpelling,
-                               SourceLoc SubscriptLoc, ParameterList *Indices,
-                               SourceLoc ArrowLoc, TypeRepr *ElementTyR,
-                               DeclContext *Parent,
-                               GenericParamList *GenericParams);
+  static SubscriptDecl *createParsed(ASTContext &Context, SourceLoc StaticLoc,
+                                     StaticSpellingKind StaticSpelling,
+                                     SourceLoc SubscriptLoc,
+                                     ParameterList *Indices, SourceLoc ArrowLoc,
+                                     TypeRepr *ElementTyR, DeclContext *Parent,
+                                     GenericParamList *GenericParams);
 
   static SubscriptDecl *create(ASTContext &Context, DeclName Name,
                                SourceLoc StaticLoc,

lib/AST/Decl.cpp

@@ -8812,14 +8812,13 @@ SubscriptDecl::createDeserialized(ASTContext &Context, DeclName Name,
   return SD;
 }
 
-SubscriptDecl *SubscriptDecl::create(ASTContext &Context, DeclName Name,
-                                     SourceLoc StaticLoc,
-                                     StaticSpellingKind StaticSpelling,
-                                     SourceLoc SubscriptLoc,
-                                     ParameterList *Indices, SourceLoc ArrowLoc,
-                                     TypeRepr *ElementTyR, DeclContext *Parent,
-                                     GenericParamList *GenericParams) {
+SubscriptDecl *SubscriptDecl::createParsed(
+    ASTContext &Context, SourceLoc StaticLoc, StaticSpellingKind StaticSpelling,
+    SourceLoc SubscriptLoc, ParameterList *Indices, SourceLoc ArrowLoc,
+    TypeRepr *ElementTyR, DeclContext *Parent,
+    GenericParamList *GenericParams) {
   assert(ElementTyR);
+  auto Name = DeclName(Context, DeclBaseName::createSubscript(), Indices);
   auto *const SD = new (Context)
       SubscriptDecl(Name, StaticLoc, StaticSpelling, SubscriptLoc, Indices,
                     ArrowLoc, ElementTyR, Parent, GenericParams);

lib/Parse/ParseDecl.cpp

@@ -9508,10 +9508,9 @@ Parser::parseDeclSubscript(SourceLoc StaticLoc,
 
   // Parse the parameter list.
   DefaultArgumentInfo DefaultArgs;
-  SmallVector<Identifier, 4> argumentNames;
-  ParserResult<ParameterList> Indices
-    = parseSingleParameterClause(ParameterContextKind::Subscript,
-                                 &argumentNames, &DefaultArgs);
+  ParserResult<ParameterList> Indices =
+      parseSingleParameterClause(ParameterContextKind::Subscript,
+                                 /*argumentNamesOut*/ nullptr, &DefaultArgs);
   Status |= Indices;
   if (Status.hasCodeCompletion() && !CodeCompletionCallbacks)
     return Status;
@@ -9554,11 +9553,9 @@ Parser::parseDeclSubscript(SourceLoc StaticLoc,
   }
 
   // Build an AST for the subscript declaration.
-  DeclName name = DeclName(Context, DeclBaseName::createSubscript(),
-                           argumentNames);
-  auto *const Subscript = SubscriptDecl::create(
-      Context, name, StaticLoc, StaticSpelling, SubscriptLoc, Indices.get(),
-      ArrowLoc, ElementTy.get(), CurDeclContext, GenericParams);
+  auto *const Subscript = SubscriptDecl::createParsed(
+      Context, StaticLoc, StaticSpelling, SubscriptLoc, Indices.get(), ArrowLoc,
+      ElementTy.get(), CurDeclContext, GenericParams);
   Subscript->getAttrs() = Attributes;
 
   // Let the source file track the opaque return type mapping, if any.