Enable comment parsing and semantic analysis to emit diagnostics.  A few
diagnostics implemented -- see testcases.

I created a new TableGen file for comment diagnostics,
DiagnosticCommentKinds.td, because comment diagnostics don't logically
fit into AST diagnostics file.  But I don't feel strongly about it.

This also implements support for self-closing HTML tags in comment
lexer and parser (for example, <br />).

In order to issue precise diagnostics CommentSema needs to know the
declaration the comment is attached to.  There is no easy way to find a decl by 
comment, so we match comments and decls in lockstep: after parsing one
declgroup we check if we have any new, not yet attached comments.  If we do --
then we do the usual comment-finding process.

It is interesting that this automatically handles trailing comments.
We pick up not only comments that precede the declaration, but also
comments that *follow* the declaration -- thanks to the lookahead in
the lexer: after parsing the declgroup we've consumed the semicolon
and looked ahead through comments.

Added -Wdocumentation-html flag for semantic HTML errors to allow the user to 
disable only HTML warnings (but not HTML parse errors, which we emit as
warnings in -Wdocumentation).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160078 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index d67fb50..8d46946 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -2952,7 +2952,9 @@
     if (InferRelatedResultType)
       ObjCMethod->SetRelatedResultType();
   }
-    
+
+  ActOnDocumentableDecl(ObjCMethod);
+
   return ObjCMethod;
 }