Closure call inlining for constant closures.

Closure call inlining for constant closures.

Until now, constant closure functions (e.g. implicit static closures) were
not considered as inlining candidates. This CL enables inlining for them.

e.g. in code like

var f = math.max;
f();

the call to f will now be inlined.

I changed the source fingerprint computation for implicit closure functions
because the signature string of implicit closure functions is different
from the parent function's.

R=vegorov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=38027

[Vyacheslav Egorov (Google), 2014-07-07 16:19:08]

lgtm

[Florian Schneider, 2014-07-07 16:22:41]

Committed patchset #1 manually as r38027 (presubmit successful).