[AST] NFC: Remove a FIXME related to ParamDecl::IsAutoClosure field

Author: xedin

include/swift/AST/Decl.h

@@ -4851,8 +4851,6 @@ class ParamDecl : public VarDecl {
   llvm::PointerIntPair<StoredDefaultArgument *, 1> DefaultValueAndIsVariadic;
 
   /// `@autoclosure` flag associated with this parameter.
-  /// FIXME: This has to become declaration attribute after
-  /// `@autoclosure` is removed from function type.
   bool IsAutoClosure = false;
 
 public:

lib/Parse/ParsePattern.cpp

@@ -486,8 +486,7 @@ mapParsedParameters(Parser &parser,
 
       // If there is `@autoclosure` attribute associated with the type
       // let's mark that in the declaration as well, because it
-      // belongs to both type flags and declaration at the moment, but
-      // should be removed from the type in the future.
+      // belongs to both type flags and declaration.
       if (auto *ATR = dyn_cast<AttributedTypeRepr>(type)) {
         auto &attrs = ATR->getAttrs();
         param->setAutoClosure(attrs.has(TypeAttrKind::TAK_autoclosure));

lib/Sema/CSSimplify.cpp

@@ -837,7 +837,7 @@ ConstraintSystem::TypeMatchResult constraints::matchCallArguments(
                             : ConstraintKind::ArgumentConversion);
 
   // Check whether argument of the call at given position refers to
-  // parameter marked as `@autoclosure. This function is used to
+  // parameter marked as `@autoclosure`. This function is used to
   // maintain source compatibility with Swift versions < 5,
   // previously examples like following used to type-check:
   //