Change the order of blocking in AllocateRegistersLocally.

Change the order of blocking in AllocateRegistersLocally.

Programmer is free to specify any register as a fixed RegisterLocation even one outside of the range available to the allocator itself.

BUG=

Committed: https://code.google.com/p/dart/source/detail?r=21577

[Vyacheslav Egorov (Google), 2013-04-16 16:58:37]

Please take a look.

I did not implement safe guarding that I described to you offline though because
it prooved to be slightly more involved and ugly than I expected.

We can still add it later.

[Vyacheslav Egorov (Google), 2013-04-16 17:00:27]

wrong version was initially uploaded. now I uploaded the right one.

[regis, 2013-04-16 17:03:12]

LGTM

[Vyacheslav Egorov (Google), 2013-04-16 20:56:05]

Committed patchset #2 manually as r21577 (presubmit successful).