Fix setting breakpoint setting in await statements

runtime/vm/token_position.h

Index: runtime/vm/token_position.h
diff --git a/runtime/vm/token_position.h b/runtime/vm/token_position.h
index b0a2062083f2b757debd3cd541b1e4c9c120ce8b..65dd3ed353eff1f555b41fef6bf97c2135c79f55 100644
--- a/runtime/vm/token_position.h
+++ b/runtime/vm/token_position.h
@@ -134,9 +134,11 @@ class TokenPosition {
   bool IsReal() const { return value_ >= kMinSourcePos; }
 
   // Is |this| a source position?
-  bool IsSourcePosition() const {
-    return IsReal() || IsNoSource() || IsSynthetic();
-  }
+  bool IsSourcePosition() const { return IsReal() || IsSynthetic(); }

[Florian Schneider, 2017/03/02 02:44:13]

This seems better. Was this another bug that NoSource was considered a soource
position before?

[hausner, 2017/03/02 06:14:00]

This function was only used in one place. It wasn't a bug per se, but I think
this makes more sense. I took the liberty to change it for this CL.

+
+  // Convert |this| into a real source position. Sentinel values remain
+  // unchanged.
+  TokenPosition SourcePosition() const { return FromSynthetic(); }
 
   // Is |this| a debug pause source position?
   bool IsDebugPause() const {