VM: Remove unused IsClosureCall bit from IC data.

VM: Remove unused IsClosureCall bit from IC data.

Since closure calls are now implemented in terms of instance calls
 (via .call and a dispatcher method), there is no need for a bit in
  the IC data tracking if a IC call may be a closure call.

R=vegorov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=39979

[Florian Schneider, 2014-09-08 16:17:17]

fschneider@google.com changed reviewers:
+ vegorov@google.com

[Florian Schneider, 2014-09-08 16:17:17]

https://codereview.chromium.org/551043002/diff/1/runtime/vm/flow_graph_compil...
File runtime/vm/flow_graph_compiler.cc (left):

https://codereview.chromium.org/551043002/diff/1/runtime/vm/flow_graph_compil...
runtime/vm/flow_graph_compiler.cc:875: if (ic_data.IsClosureCall()) {
This code has effectively become unreachable, because the IC miss handler always
enters a target (normal method, or a closure dispatcher method) into the IC data
the first time around.

So ic_data.NumberOfUsedChecks() is never zero for closure calls if they have
been executed before optimizing.

If they have not been executed before optimizing, IsClosureCall is naturally
false.

[Vyacheslav Egorov (Google), 2014-09-08 17:01:23]

lgtm

[Florian Schneider, 2014-09-08 17:11:08]

Committed patchset #1 (id:1) manually as r39979 (presubmit successful).