Fix for issue 4638 in bitmap builder.

Fix for issue 4638 in bitmap builder.
- Check for maximum size of byte offset and fatal out if it is larger.
- Convert some of the InRange asserts to actual checks.

R=srdjan@google.com

Committed: https://code.google.com/p/dart/source/detail?r=23637

[srdjan, 2013-06-05 15:57:21]

LGTM

https://codereview.chromium.org/16356009/diff/1/runtime/vm/bitmap.cc
File runtime/vm/bitmap.cc (right):

https://codereview.chromium.org/16356009/diff/1/runtime/vm/bitmap.cc#newcode95
runtime/vm/bitmap.cc:95: return;
FATAL instead of return

[siva, 2013-06-05 16:22:09]

https://codereview.chromium.org/16356009/diff/1/runtime/vm/bitmap.cc
File runtime/vm/bitmap.cc (right):

https://codereview.chromium.org/16356009/diff/1/runtime/vm/bitmap.cc#newcode95
runtime/vm/bitmap.cc:95: return;
On 2013/06/05 15:57:21, srdjan wrote:
> FATAL instead of return

Done.

[siva, 2013-06-05 16:42:41]

Committed patchset #1 manually as r23637 (presubmit successful).