fix PPC debug-only build breakage

--HG--
extra : convert_revision : 6b99983c6b88ce05809d05e4e2b24836a1c2724e

js/src/nanojit/NativePPC.cpp

@@ -1231,7 +1231,7 @@ namespace nanojit
         verbose_only(if (_logc->lcbits & LC_Assembly) outputf("%p:",after);)
         MR(rr,rf);
 
-        NanoAssert(isS14(after - (_nIns-1)));
+        NanoAssert(isS24(after - (_nIns-1)));
         asm_branch_near(false, condval, after);
 
         if (rr != rt)