Made the enum JSErrNum into a typedef

enum JSErrNum, and changed a uintN
errorNumber declaration to JSErrNum.

It'd be nice to change the uintN
errorNumber field in JSErrorReport to
JSErrNum, but it's not clear that
JSErrNum is or should be exposed in the
API.  Any C esthetes want to offer their
opinions?

It made my debugger slightly happier.

js/ref/jscntxt.h

@@ -209,14 +209,14 @@ js_ReportErrorAgain(JSContext *cx, const char *message, JSErrorReport *report);
 extern void
 js_ReportIsNotDefined(JSContext *cx, const char *name);
 
-enum JSErrNum {
+typedef enum JSErrNum {
 #define MSG_DEF(name, number, count, exception, format) \
     name = number,
 #include "jsmsg.def"
 #undef MSG_DEF
     JSErr_Limit
 #undef MSGDEF
-};
+} JSErrNum;
 
 extern JSErrorFormatString js_ErrorFormatString[JSErr_Limit];
 

js/ref/jsexn.c

@@ -188,7 +188,7 @@ static JSExnType errorToException[] = {
 
 JSBool
 js_ErrorToException(JSContext *cx, JSErrorReport *reportp) {
-    uintN errorNumber;
+    JSErrNum errorNumber; 
     JSObject *errobj;
     JSExnType exn;