Implement AST classes for comments, a real parser for Doxygen comments and a
very simple semantic analysis that just builds the AST; minor changes for lexer
to pick up source locations I didn't think about before.

Comments AST is modelled along the ideas of HTML AST: block and inline content.

* Block content is a paragraph or a command that has a paragraph as an argument
  or verbatim command.
* Inline content is placed within some block.  Inline content includes plain
  text, inline commands and HTML as tag soup.

llvm-svn: 159790
diff --git a/clang/lib/AST/CMakeLists.txt b/clang/lib/AST/CMakeLists.txt
index 5dad60c..c45f721 100644
--- a/clang/lib/AST/CMakeLists.txt
+++ b/clang/lib/AST/CMakeLists.txt
@@ -8,8 +8,12 @@
   ASTImporter.cpp
   AttrImpl.cpp
   CXXInheritance.cpp
+  Comment.cpp
   CommentBriefParser.cpp
+  CommentDumper.cpp
   CommentLexer.cpp
+  CommentParser.cpp
+  CommentSema.cpp
   Decl.cpp
   DeclarationName.cpp
   DeclBase.cpp
@@ -60,6 +64,7 @@
   ClangAttrList
   ClangAttrImpl
   ClangDiagnosticAST
+  ClangCommentNodes
   ClangDeclNodes
   ClangStmtNodes
   )