Support spawnUri in app snapshots.

Support spawnUri in app snapshots.

 - Don't mark core_isolate_snapshot_buffer as a const pointer.
 - Update app snapshots without code to not rewrite the VM isolate snapshot, as already done by app snapshots with code.

Fixes #28368

R=asiva@google.com

Committed: https://github.com/dart-lang/sdk/commit/26a364f9988b502df07b3c633cfc4022e3f28fa5

[rmacnak, 2017-01-17 18:42:21]

rmacnak@google.com changed reviewers:
+ asiva@google.com

[rmacnak, 2017-01-17 18:42:22]

https://codereview.chromium.org/2637193002/diff/1/runtime/bin/main.cc
File runtime/bin/main.cc (left):

https://codereview.chromium.org/2637193002/diff/1/runtime/bin/main.cc#oldcode...
runtime/bin/main.cc:1526: uint8_t* vm_isolate_buffer = NULL;
Rewriting the vm isolate here created a mismatch between the vm isolate expected
by the app snapshot and the one expected by the core snapshot.

[siva, 2017-01-17 22:55:00]

lgtm

[rmacnak, 2017-01-17 23:59:47]

Description was changed from

==========
Support spawnUri in app snapshots.

 - Don't mark core_isolate_snapshot_buffer as a const pointer.
 - Update app snapshots without code to not rewrite the VM isolate snapshot, as
already done by app snapshots with code.

Fixes #28368
==========

to

==========
Support spawnUri in app snapshots.

 - Don't mark core_isolate_snapshot_buffer as a const pointer.
 - Update app snapshots without code to not rewrite the VM isolate snapshot, as
already done by app snapshots with code.

Fixes #28368

R=asiva@google.com

Committed:
https://github.com/dart-lang/sdk/commit/26a364f9988b502df07b3c633cfc4022e3f28fa5
==========

[rmacnak, 2017-01-17 23:59:48]

Committed patchset #1 (id:1) manually as
26a364f9988b502df07b3c633cfc4022e3f28fa5 (presubmit successful).