eliminate TypeBase::getRelabeledType()

We used to build the type for a parameter types and then relabeling
them from the DeclName.  Now we build the ParameterList and use that
to construct the DeclName.  Since we get the parameter list type from
the same ParameterList, it is always properly labeled.  NFC.

Author: lattner

include/swift/AST/Types.h

@@ -672,10 +672,6 @@ class alignas(1 << TypeAlignInBits) TypeBase {
   /// the result would be the (parenthesized) type ((int, int)).
   Type getUnlabeledType(ASTContext &Context);
 
-  /// Relabel the elements of the given type with the given new
-  /// (top-level) labels.
-  Type getRelabeledType(ASTContext &Context, ArrayRef<Identifier> labels);
-
   /// \brief Retrieve the type without any default arguments.
   Type getWithoutDefaultArgs(const ASTContext &Context);
 

lib/AST/Type.cpp

@@ -765,38 +765,6 @@ Type TypeBase::getUnlabeledType(ASTContext &Context) {
                          /*defaultArgs=*/true);
 }
 
-Type TypeBase::getRelabeledType(ASTContext &ctx, 
-                                ArrayRef<Identifier> labels) {
-  if (auto tupleTy = dyn_cast<TupleType>(this)) {
-    assert(labels.size() == tupleTy->getNumElements() && 
-           "Wrong number of labels");
-    SmallVector<TupleTypeElt, 4> elements;
-    unsigned i = 0;
-    bool anyChanged = false;
-    for (const auto &elt : tupleTy->getElements()) {
-      if (elt.getName() != labels[i])
-        anyChanged = true;
-
-      elements.push_back(TupleTypeElt(elt.getType(), labels[i], 
-                                      elt.getDefaultArgKind(), elt.isVararg()));
-      ++i;
-    }
-
-    if (!anyChanged)
-      return this;
-
-    return TupleType::get(elements, ctx);
-  }
-
-  // If there is no label, the type is unchanged.
-  if (labels[0].empty())
-    return this;
-
-  // Create a one-element tuple to capture the label.
-  TupleTypeElt elt(this, labels[0]);
-  return TupleType::get(elt, ctx);  
-}
-
 Type TypeBase::getWithoutDefaultArgs(const ASTContext &Context) {
   return getStrippedType(Context, Type(this), /*labels=*/false,
                          /*defaultArgs=*/true);

lib/Sema/TypeCheckDecl.cpp

@@ -1356,10 +1356,6 @@ void swift::configureConstructorType(ConstructorDecl *ctor,
     resultType = OptionalType::get(ctor->getFailability(), resultType);
   }
 
-  // Use the argument names in the argument type.
-  argType = argType->getRelabeledType(ctor->getASTContext(), 
-                                      ctor->getFullName().getArgumentNames());
-
   auto extInfo = AnyFunctionType::ExtInfo().withThrows(throws);
 
   GenericParamList *outerGenericParams =

lib/Sema/TypeCheckPattern.cpp

@@ -1582,8 +1582,6 @@ bool TypeChecker::coercePatternToType(Pattern *&P, DeclContext *dc, Type type,
 ///
 bool TypeChecker::coerceParameterListToType(ParameterList *P, DeclContext *DC,
                                             Type paramListType) {
-  TypeResolutionOptions options;
-
   bool hadError = paramListType->is<ErrorType>();
 
   // Sometimes a scalar type gets applied to a single-argument parameter list.
@@ -1592,7 +1590,8 @@ bool TypeChecker::coerceParameterListToType(ParameterList *P, DeclContext *DC,
 
     // Check that the type, if explicitly spelled, is ok.
     if (param.type.getTypeRepr()) {
-      hadError |= validateParameterType(param, DC, options, nullptr, *this);
+      hadError |= validateParameterType(param, DC, TypeResolutionOptions(),
+                                        nullptr, *this);
 
       // Now that we've type checked the explicit argument type, see if it
       // agrees with the contextual type.