Speedup function profile by using a hash table instead of a linear scan

runtime/vm/profiler_service.h

Index: runtime/vm/profiler_service.h
diff --git a/runtime/vm/profiler_service.h b/runtime/vm/profiler_service.h
index 4bd64da740283b6478f04b69efff3a5f71f00fb2..269ce1dd0238ef6b238b79b7fc1ad6016320c3be 100644
--- a/runtime/vm/profiler_service.h
+++ b/runtime/vm/profiler_service.h
@@ -77,6 +77,10 @@ class ProfileFunction : public ZoneAllocated {
     return function_.raw();
   }
 
+  const Function* key() const {
+    return &function_;
+  }

[Ivan Posva, 2016/03/23 15:14:40]

Looking at this again this definitely should be consolidated to this being the
function() accessor.

[Cutch, 2016/03/23 19:34:21]

Done.

+
   intptr_t table_index() const {
     return table_index_;
   }