Again reverting an attempt to convert the DeclSpec enums into scoped enums.
  - reverts r321622, r321625, and r321626.
  - the use of bit-fields is still resulting in warnings - even though we can use static-asserts to harden the code and ensure the bit-fields are wide enough.  The bots still complain of warnings being seen.
  - to silence the warnings requires specifying the bit-fields with the underlying enum type (as opposed to the enum type itself), which then requires lots of unnecessary static casts of each enumerator within DeclSpec to the underlying-type, which even though could be seen as implementation details, it does hamper readability - and given the additional litterings, makes me question the value of the change.

So in short - I give up (for now at least).  

Sorry about the noise.

llvm-svn: 321628
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 8953eef..68b73ca 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -1011,12 +1011,10 @@
     PP.EnterToken(Tok);
 
   Tok.setKind(tok::annot_decltype);
-  setExprAnnotation(Tok, DS.getTypeSpecType() == TypeSpecifierType::TST_decltype
-                             ? DS.getRepAsExpr()
-                             : DS.getTypeSpecType() ==
-                                       TypeSpecifierType::TST_decltype_auto
-                                   ? ExprResult()
-                                   : ExprError());
+  setExprAnnotation(Tok,
+                    DS.getTypeSpecType() == TST_decltype ? DS.getRepAsExpr() :
+                    DS.getTypeSpecType() == TST_decltype_auto ? ExprResult() :
+                    ExprError());
   Tok.setAnnotationEndLoc(EndLoc);
   Tok.setLocation(StartLoc);
   PP.AnnotateCachedTokens(Tok);
@@ -1196,8 +1194,8 @@
 
   const char *PrevSpec = nullptr;
   unsigned DiagID;
-  DS.SetTypeSpecType(TypeSpecifierType::TST_typename, IdLoc, PrevSpec, DiagID,
-                     Type, Actions.getASTContext().getPrintingPolicy());
+  DS.SetTypeSpecType(TST_typename, IdLoc, PrevSpec, DiagID, Type,
+                     Actions.getASTContext().getPrintingPolicy());
 
   Declarator DeclaratorInfo(DS, DeclaratorContext::TypeNameContext);
   return Actions.ActOnTypeName(getCurScope(), DeclaratorInfo);
@@ -2954,8 +2952,7 @@
 
 void Parser::SkipCXXMemberSpecification(SourceLocation RecordLoc,
                                         SourceLocation AttrFixitLoc,
-                                        TypeSpecifierType TagType,
-                                        Decl *TagDecl) {
+                                        unsigned TagType, Decl *TagDecl) {
   // Skip the optional 'final' keyword.
   if (getLangOpts().CPlusPlus && Tok.is(tok::identifier)) {
     assert(isCXX11FinalKeyword() && "not a class definition");
@@ -3107,12 +3104,11 @@
 void Parser::ParseCXXMemberSpecification(SourceLocation RecordLoc,
                                          SourceLocation AttrFixitLoc,
                                          ParsedAttributesWithRange &Attrs,
-                                         TypeSpecifierType TagType,
-                                         Decl *TagDecl) {
+                                         unsigned TagType, Decl *TagDecl) {
   assert((TagType == DeclSpec::TST_struct ||
-          TagType == DeclSpec::TST_interface ||
-          TagType == DeclSpec::TST_union || TagType == DeclSpec::TST_class) &&
-         "Invalid TagType!");
+         TagType == DeclSpec::TST_interface ||
+         TagType == DeclSpec::TST_union  ||
+         TagType == DeclSpec::TST_class) && "Invalid TagType!");
 
   PrettyDeclStackTraceEntry CrashInfo(Actions, TagDecl, RecordLoc,
                                       "parsing struct/union/class body");