Remove @autoclosure and @noescape as decl attributes

Using these in declaration position has been deprecated and
removed in Swift 3.  These attributes were not being parsed and
contained deadweight diagnostics that should have been moved
when these attributes became type attributes.

lib/Serialization/Deserialization.cpp

@@ -2267,16 +2267,6 @@ ModuleFile::getDeclChecked(DeclID DID, Optional<DeclContext *> ForcedContext) {
 #undef DECODE_VER_TUPLE
       }
 
-      case decls_block::AutoClosure_DECL_ATTR: {
-        bool isImplicit;
-        bool isEscaping;
-        serialization::decls_block::AutoClosureDeclAttrLayout::readRecord(
-          scratch, isImplicit, isEscaping);
-        Attr = new (ctx) AutoClosureAttr(SourceLoc(), SourceRange(),
-                                         isEscaping, isImplicit);
-        break;
-      }
-
       case decls_block::ObjC_DECL_ATTR: {
         bool isImplicit;
         bool isImplicitName;