Moves the top_ and end_ words of the Scavenger into mutator thread.

Moves the top_ and end_ words of the Scavenger into mutator thread.

This is the first step to adding Thread Local Allocation Buffers to
the VM.

In this step, the mutator alone allocates to the new space, but keeps
track of the start and end of the space. This is akin to a single large
TLAB.

As a result, the generated code and the dbc simulator changed how they
allocate objects into the new space as well.

R=rmacnak@google.com

Committed: https://github.com/dart-lang/sdk/commit/699f84f94141e405330ab1bd15dc7b58ba3067df

[danunez, 2017-07-13 19:45:55]

Fixes what broke the DBC simulator in the last CL.

[rmacnak, 2017-07-13 20:44:58]

lgtm

[danunez, 2017-07-13 20:46:21]

Description was changed from

==========
Moves the top_ and end_ words of the Scavenger into mutator thread.

This is the first step to adding Thread Local Allocation Buffers to
the VM.

In this step, the mutator alone allocates to the new space, but keeps
track of the start and end of the space. This is akin to a single large
TLAB.

As a result, the generated code and the dbc simulator changed how they
allocate objects into the new space as well.
R=rmacnak@google.com
==========

to

==========
Moves the top_ and end_ words of the Scavenger into mutator thread.

This is the first step to adding Thread Local Allocation Buffers to
the VM.

In this step, the mutator alone allocates to the new space, but keeps
track of the start and end of the space. This is akin to a single large
TLAB.

As a result, the generated code and the dbc simulator changed how they
allocate objects into the new space as well.

R=rmacnak@google.com

Committed:
https://github.com/dart-lang/sdk/commit/699f84f94141e405330ab1bd15dc7b58ba3067df
==========

[danunez, 2017-07-13 20:46:22]

Committed patchset #1 (id:1) manually as
699f84f94141e405330ab1bd15dc7b58ba3067df (presubmit successful).