Fix from Martin Husemann <martin@NetBSD.ORG> for int-instead-of-ptrdiff_t abusage (361362, r=me).

js/src/jsemit.c

@@ -3866,7 +3866,7 @@ js_EmitTree(JSContext *cx, JSCodeGenerator *cg, JSParseNode *pn)
     JSAtom *atom;
     JSAtomListElement *ale;
     jsatomid atomIndex;
-    intN noteIndex;
+    ptrdiff_t noteIndex;
     JSSrcNoteType noteType;
     jsbytecode *pc;
     JSOp op;