EMACS_INT to EMACS_UINT

[Ravi Desai]

Hello all,

I've been trying to familiarize myself with the emacs source at the 
C-level, and while I was looking at src/lisp.h I noticed that while 'XLI 
(a)' should return an EMACS_INT, we expect it to be a EMACS_UINT in the 
definition of 'XTYPE'.

---
/* Extract A's type.  */
INLINE enum Lisp_Type
XTYPE (Lisp_Object a)
{
  EMACS_UINT i = XLI (a); // <---- This seems strange to me.
  return USE_LSB_TAG ? i & ~VALMASK : i >> VALBITS;
}
---

Is this something that we should change? The code is working, so I don't 
know if its a big enough deal.