[heap] Fix check in AdvancePage

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index 29a0b66d9de1ae4ea8b4614ba970eaaa1e68eb52..eec533f9a1e01a4c470fc274c809ddde59234923 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -2459,7 +2459,11 @@ class SemiSpace : public Space {
 
   bool AdvancePage() {
     Page* next_page = current_page_->next_page();
-    if (next_page == anchor() || pages_used_ == max_pages()) {
+    // We cannot expand if we reached the maximum number of pages already. Note
+    // that we need to account for the next page already for this check as we
+    // could potentially fill the whole page after advancing.
+    const bool reached_max_pages = (pages_used_ + 1) == max_pages();
+    if (next_page == anchor() || reached_max_pages) {
       return false;
     }
     current_page_ = next_page;