swift234

build the final, happy AST for integer literals.  For example, this:

import swift
var c : int8 = 4 

becomes:

(translation_unit
  (brace_stmt
    (import_decl 'swift')
    (var_decl 'c' type='int8'
      (call_expr type='int8'
        (declref_expr type='(val : int8) -> int8' decl=convert_from_integer_literal)
        (integer_literal_expr type='int8' value=4)))))    <<- this is Builtin::int8

... which is finally great.  The only problem is that it causes massive explosions 
in IRGen, which isn't expecting this yet.  I'll look at this this evening if John
doesn't beat me to it :)


Swift SVN r954