[Fuchsia] Give VMOs names

runtime/vm/heap.h

Index: runtime/vm/heap.h
diff --git a/runtime/vm/heap.h b/runtime/vm/heap.h
index 64b7499d7962a25f0b85cf721737264c3ca1aa5c..f67637f3c2881fa9cc9d2ff37d42b4700f42fbf7 100644
--- a/runtime/vm/heap.h
+++ b/runtime/vm/heap.h
@@ -138,6 +138,9 @@ class Heap {
                    intptr_t max_old_gen_words,
                    intptr_t max_external_words);
 
+  // Writes a suitable name for a VM region in the heap into the buffer `name`.
+  void RegionName(Space space, char* name, intptr_t name_size);
+
   // Verify that all pointers in the heap point to the heap.
   bool Verify(MarkExpectation mark_expectation = kForbidMarked) const;