[Fuchsia] Give VMOs names

runtime/vm/scavenger.h

Index: runtime/vm/scavenger.h
diff --git a/runtime/vm/scavenger.h b/runtime/vm/scavenger.h
index 7fa3950f701eb2847e9356e43f952552e8f01699..b0e5dca273c7805b3a95092376bbd693523c6f9e 100644
--- a/runtime/vm/scavenger.h
+++ b/runtime/vm/scavenger.h
@@ -32,7 +32,9 @@ class SemiSpace {
 
   // Get a space of the given size. Returns NULL on out of memory. If size is 0,
   // returns an empty space: pointer(), start() and end() all return NULL.
-  static SemiSpace* New(intptr_t size_in_words);
+  // The name parameter may be NULL. If non-NULL it is ued to give the OS a name
+  // for the underlying virtual memory region.
+  static SemiSpace* New(intptr_t size_in_words, const char* name);
 
   // Hand back an unused space.
   void Delete();