Implement resolving of HTML character references (named: &, decimal: *,
hex: ) during comment parsing.

Now internal representation of plain text in comment AST does not contain
character references, but the characters themselves.

llvm-svn: 160891
diff --git a/clang/unittests/AST/CommentParser.cpp b/clang/unittests/AST/CommentParser.cpp
index 47433ae..ff93195 100644
--- a/clang/unittests/AST/CommentParser.cpp
+++ b/clang/unittests/AST/CommentParser.cpp
@@ -54,7 +54,7 @@
   FileID File = SourceMgr.createFileIDForMemBuffer(Buf);
   SourceLocation Begin = SourceMgr.getLocForStartOfFile(File);
 
-  comments::Lexer L(Begin, CommentOptions(),
+  comments::Lexer L(Allocator, Begin, CommentOptions(),
                     Source, Source + strlen(Source));
 
   comments::Sema S(Allocator, SourceMgr, Diags);