Greetings,

Here is a new patch for user-defined literals.
* New C preprocessor tokens are defined for numbers, chars, and strings 
with suffixes are defined.  They are lexed as complete tokens.
* The new tokens are passed through the C tokenized to the C++ tokenizer 
and parser and so on.
* There is a new tree code and structure for user defined literals.
* Char type literals are completely finished.
* String type literals are completely finished including concatenation, 
raw literals, etc.
* Numeric literals are *mostly* done (numeric argument operators and the 
raw literal operator (const char *) forms are supported.
* LTO serialization seems to work.  I'm storing the trees in my struct 
rather than refs.
* All the checks (except noted below) for arguments are made.
* All the checks I could find concerning scope and linkage are made.
* Like before I issue a warning if the user-defined suffix for numeric 
types is shadowed by our implementation
   which includes not only the usual standard ones but several 
extensions as well.
* You can't call the suffix as a function anymore (That was an error, 
I'm mangling to __udlit<suffix> now).

There are some issues:
* Friend operators don't work.  Literal operators can't be class members 
but they could be friends.
* The template numeric literals don't work:
    template<char...Char>
     X operator"" QQQ();
   - You *can* explicitly call the operator:
         cout << operator"" QQQ<'A','B','C'>();
   - The template parameters are *not* checked
   - The void argument is *not* checked.
* Someday, we'll want to move Objective-C++ strings into the C++ string 
lexer like it says in the notes.
    I think we'll want to do some minimal surprise thing like *not* 
allow @ strings to have suffixes.
    I can't see a reason someone can't return an @ string from a 
user-defined literal though.

I'm sure there are functional and aesthetic comments that people can make.

Have at it ;-)

Ed Smith-Rowland