Move Zone's destructor out of a header file.

Move Zone's destructor out of a header file.

This unburdens users of StackZone from needing to include handles_impl.h. A new use of StackZone was recently added to heap.cc without a include of handles_impl.h, and this caused link-time errors on some versions of gcc.

R=asiva@google.com

Committed: https://github.com/dart-lang/sdk/commit/326af5e9d7de8863ab4141a42f8dd8513d8f408c

[rmacnak, 2016-09-22 00:40:37]

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

[siva, 2016-09-22 19:33:18]

lgtm

[rmacnak, 2016-09-22 20:16:41]

Description was changed from

==========
Move Zone's destructor out of a header file.

This unburdens users of StackZone from needing to include handles_impl.h. A new
use of StackZone was recently added to heap.cc without a include of
handles_impl.h, and this caused link-time errors on some versions of gcc.
==========

to

==========
Move Zone's destructor out of a header file.

This unburdens users of StackZone from needing to include handles_impl.h. A new
use of StackZone was recently added to heap.cc without a include of
handles_impl.h, and this caused link-time errors on some versions of gcc.

R=asiva@google.com

Committed:
https://github.com/dart-lang/sdk/commit/326af5e9d7de8863ab4141a42f8dd8513d8f408c
==========

[rmacnak, 2016-09-22 20:16:42]

Committed patchset #2 (id:20001) manually as
326af5e9d7de8863ab4141a42f8dd8513d8f408c (presubmit successful).