Reapply "Fix misoptimization of 'is' test""

Reapply "Fix misoptimization of 'is' test""

This also moves some common code from jit_optimizer.cc and
aot_optimizer.cc to a new common file, optimizer.cc. The code is almost
unchanged from the aot_optimizer.cc version, apart from the calls to
PurgeNegativeTestCidsEntries.  A flag emulates the behaviour of the
simpler jit_optimizer.cc version.  Benchmark tests are running to see
which is better.

Originally reviewed at https://codereview.chromium.org/2904543002/

R=vegorov@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/8619cb63878d5be7ad714f1eb5867cc828d0d1e9

[Vyacheslav Egorov (Google), 2017-05-30 10:54:20]

lgtm

https://codereview.chromium.org/2912903002/diff/20001/runtime/vm/intermediate...
File runtime/vm/intermediate_language.cc (right):

https://codereview.chromium.org/2912903002/diff/20001/runtime/vm/intermediate...
runtime/vm/intermediate_language.cc:3892: if (CanDeoptimize() !=
other->CanDeoptimize()) {
I don't think CanDeoptimize() should be compared here, it does not matter if
they match as long as they compare the same thing they can be used
interchangeably.

[Vyacheslav Egorov (Google), 2017-05-30 11:29:48]

lgtm

[erikcorry, 2017-05-30 12:17:12]

Description was changed from

==========
Reapply "Fix misoptimization of 'is' test""

This also moves some common code from jit_optimizer.cc and
aot_optimizer.cc to a new common file, optimizer.cc. The code is almost
unchanged from the aot_optimizer.cc version, apart from the calls to
PurgeNegativeTestCidsEntries.  A flag emulates the behaviour of the
simpler jit_optimizer.cc version.  Benchmark tests are running to see
which is better.

Originally reviewed at https://codereview.chromium.org/2904543002/

R=vegorov@google.com
BUG=
==========

to

==========
Reapply "Fix misoptimization of 'is' test""

This also moves some common code from jit_optimizer.cc and
aot_optimizer.cc to a new common file, optimizer.cc. The code is almost
unchanged from the aot_optimizer.cc version, apart from the calls to
PurgeNegativeTestCidsEntries.  A flag emulates the behaviour of the
simpler jit_optimizer.cc version.  Benchmark tests are running to see
which is better.

Originally reviewed at https://codereview.chromium.org/2904543002/

R=vegorov@google.com
BUG=

Committed:
https://github.com/dart-lang/sdk/commit/8619cb63878d5be7ad714f1eb5867cc828d0d1e9
==========

[erikcorry, 2017-05-30 12:17:13]

Committed patchset #3 (id:40001) manually as
8619cb63878d5be7ad714f1eb5867cc828d0d1e9 (presubmit successful).