Bug 1383206 - Fix format string for in GC slice statistics. r=sfink

MozReview-Commit-ID: 7eLrYNtb4jv

--HG--
extra : rebase_source : da1e37628a8056f16a025443869792dc9f217e83

js/src/gc/Statistics.cpp

@@ -451,7 +451,7 @@ Statistics::formatDetailedSliceDescription(unsigned i, const SliceData& slice) c
     Reason: %s\n\
     Reset: %s%s\n\
     State: %s -> %s\n\
-    Page Faults: %ld\n\
+    Page Faults: %" PRIu64 "\n\
     Pause: %.3fms of %s budget (@ %.3fms)\n\
 ";
     char buffer[1024];