Push DeclGroup much farther throughout the compiler.  Now the various
productions (except the already broken ObjC cases like @class X,Y;) in 
the parser that can produce more than one Decl return a DeclGroup instead
of a Decl, etc.

This allows elimination of the Decl::NextDeclarator field, and exposes
various clients that should look at all decls in a group, but which were
only looking at one (such as the dumper, printer, etc).  These have been
fixed.

Still TODO:

1) there are some FIXME's in the code about potentially using
DeclGroup for better location info.
2) ParseObjCAtDirectives should return a DeclGroup due to @class etc.
3) I'm not sure what is going on with StmtIterator.cpp, or if it can
   be radically simplified now.
4) I put a truly horrible hack in ParseTemplate.cpp.

I plan to bring up #3/4 on the mailing list, but don't plan to tackle
#1/2 in the short term.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68002 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/ParseAST.cpp b/lib/Sema/ParseAST.cpp
index 59a04da..4bcb478 100644
--- a/lib/Sema/ParseAST.cpp
+++ b/lib/Sema/ParseAST.cpp
@@ -44,16 +44,14 @@
   
   Consumer->Initialize(Ctx);
   
-  Parser::DeclPtrTy ADecl;
+  Parser::DeclGroupPtrTy ADecl;
   
   while (!P.ParseTopLevelDecl(ADecl)) {  // Not end of file.
     // If we got a null return and something *was* parsed, ignore it.  This
     // is due to a top-level semicolon, an action override, or a parse error
     // skipping something.
-    if (ADecl) {
-      Decl *D = ADecl.getAs<Decl>();      
-      Consumer->HandleTopLevelDecl(D);
-    }
+    if (ADecl)
+      Consumer->HandleTopLevelDecl(ADecl.getAsVal<DeclGroupRef>());
   };
   
   Consumer->HandleTranslationUnit(Ctx);