Fix the paged space statistics report error under debug mode.

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 2b696ea8eb5238f91f5ade5702cc663f4c09cc73..aa244ad94a1f86d27a148e6a8c484173b31af9da 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -2791,7 +2791,8 @@ void PagedSpace::CollectCodeStatistics() {
 
 
 void PagedSpace::ReportStatistics() {
-  int pct = static_cast<int>(Available() * 100 / Capacity());
+  int pct = Capacity() > 0 ? static_cast<int>(Available() * 100 / Capacity())
+                           : 0;
   PrintF("  capacity: %" V8_PTR_PREFIX
          "d"
          ", waste: %" V8_PTR_PREFIX