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/tools/clang-cc/ASTConsumers.cpp b/tools/clang-cc/ASTConsumers.cpp
index cb09659..3910c77 100644
--- a/tools/clang-cc/ASTConsumers.cpp
+++ b/tools/clang-cc/ASTConsumers.cpp
@@ -539,8 +539,9 @@
   public:
     ASTPrinter(llvm::raw_ostream* o = NULL) : DeclPrinter(o) {}
     
-    virtual void HandleTopLevelDecl(Decl *D) {
-      PrintDecl(D);
+    virtual void HandleTopLevelDecl(DeclGroupRef D) {
+      for (DeclGroupRef::iterator I = D.begin(), E = D.end(); I != E; ++I)
+        PrintDecl(*I);
     }
   };
 } // end anonymous namespace
@@ -562,11 +563,15 @@
       SM = &Context.getSourceManager();
     }
 
-    virtual void HandleTopLevelDecl(Decl *D);
+    virtual void HandleTopLevelDecl(DeclGroupRef D) {
+      for (DeclGroupRef::iterator I = D.begin(), E = D.end(); I != E; ++I)
+        HandleTopLevelSingleDecl(*I);
+    }
+    void HandleTopLevelSingleDecl(Decl *D);
   };
 } // end anonymous namespace
 
-void ASTDumper::HandleTopLevelDecl(Decl *D) {
+void ASTDumper::HandleTopLevelSingleDecl(Decl *D) {
   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
     PrintFunctionDeclStart(FD);
     
@@ -624,12 +629,17 @@
     void Initialize(ASTContext &Context) {
       SM = &Context.getSourceManager();
     }
+
+    virtual void HandleTopLevelDecl(DeclGroupRef D) {
+      for (DeclGroupRef::iterator I = D.begin(), E = D.end(); I != E; ++I)
+        HandleTopLevelSingleDecl(*I);
+    }
     
-    virtual void HandleTopLevelDecl(Decl *D);
+    void HandleTopLevelSingleDecl(Decl *D);
   };
 }
 
-void ASTViewer::HandleTopLevelDecl(Decl *D) {
+void ASTViewer::HandleTopLevelSingleDecl(Decl *D) {
   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
     DeclPrinter().PrintFunctionDeclStart(FD);