Simplify and fix implicit closure check, speed up Closure_equals, v2

Simplify and fix implicit closure check, speed up Closure_equals, v2

This is the re-application of 44e8da3ecd23de5fdd022d6de0d2ec895cc37beb
with fixes:
* Dartanalyzer error is fixed in the new test isolate/message4_test
* The new test is skipped in the status file in dart2j/non-d8 modes,
  issue #30247 is created.
* Minor tweak of Closure_equals: other.IsClosure() is tested earlier.

Original CL review:

https://codereview.chromium.org/2989493002/

Original CL description:

This CL introduces a new Function kind, kImplicitClosureFunction, in
order to simplify check for implicit closures and make it more
efficient.

This CL also fixes Function::IsImplicitStaticClosureFunction(RawFunction*)
to correctly handle implicit closures created from static native
functions.

Closes #30203.

As the result of a faster check for implicit closures and slight
refactoring of Closure_equals, micro-benchmark exercising Closure_equals
speeds up from 9618ms to 6700ms for implicit closures case and
insignificantly for other cases.

R=zra@google.com

Committed: https://github.com/dart-lang/sdk/commit/bda3c9c2b24f4d1b98c2e333bbc0d09bcc81f14c

[alexmarkov, 2017-07-24 16:09:42]

alexmarkov@google.com changed reviewers:
+ asiva@google.com, rmacnak@google.com, zra@google.com

[zra, 2017-07-24 16:41:23]

lgtm

[alexmarkov, 2017-07-24 16:43:57]

Description was changed from

==========
Simplify and fix implicit closure check, speed up Closure_equals, v2

This is the re-application of 44e8da3ecd23de5fdd022d6de0d2ec895cc37beb
with fixes:
* Dartanalyzer error is fixed in the new test isolate/message4_test
* The new test is skipped in the status file in dart2j/non-d8 modes,
  issue #30247 is created.
* Minor tweak of Closure_equals: other.IsClosure() is tested earlier.

Original CL review:

https://codereview.chromium.org/2989493002/

Original CL description:

This CL introduces a new Function kind, kImplicitClosureFunction, in
order to simplify check for implicit closures and make it more
efficient.

This CL also fixes Function::IsImplicitStaticClosureFunction(RawFunction*)
to correctly handle implicit closures created from static native
functions.

Closes #30203.

As the result of a faster check for implicit closures and slight
refactoring of Closure_equals, micro-benchmark exercising Closure_equals
speeds up from 9618ms to 6700ms for implicit closures case and
insignificantly for other cases.
==========

to

==========
Simplify and fix implicit closure check, speed up Closure_equals, v2

This is the re-application of 44e8da3ecd23de5fdd022d6de0d2ec895cc37beb
with fixes:
* Dartanalyzer error is fixed in the new test isolate/message4_test
* The new test is skipped in the status file in dart2j/non-d8 modes,
  issue #30247 is created.
* Minor tweak of Closure_equals: other.IsClosure() is tested earlier.

Original CL review:

https://codereview.chromium.org/2989493002/

Original CL description:

This CL introduces a new Function kind, kImplicitClosureFunction, in
order to simplify check for implicit closures and make it more
efficient.

This CL also fixes Function::IsImplicitStaticClosureFunction(RawFunction*)
to correctly handle implicit closures created from static native
functions.

Closes #30203.

As the result of a faster check for implicit closures and slight
refactoring of Closure_equals, micro-benchmark exercising Closure_equals
speeds up from 9618ms to 6700ms for implicit closures case and
insignificantly for other cases.

R=zra@google.com

Committed:
https://github.com/dart-lang/sdk/commit/bda3c9c2b24f4d1b98c2e333bbc0d09bcc81f14c
==========

[alexmarkov, 2017-07-24 16:43:59]

Committed patchset #1 (id:1) manually as
bda3c9c2b24f4d1b98c2e333bbc0d09bcc81f14c (presubmit successful).