Enable inlining of functions that reference context slots.

Enable inlining of functions that reference context slots.
Committed: http://code.google.com/p/v8/source/detail?r=9294

[William Hesse, 2011-09-15 00:07:06]

I'm not sure that you test the case that f.run has an inner context here.  Does
!Lookup cover both the static lookup and dynamic lookup of context slots?  If
not, will a statically computed lookup in the context chain be compiled
correctly if a function is inlined?  Exactly what inlining cases do we allow? 
When the context of the inlining function equals the context of the inlined
function, even if the inlining function has context slots, and thus a new inner
context?

[Kevin Millikin (Chromium), 2011-09-15 09:45:01]

LGTM.

http://codereview.chromium.org/7887038/diff/1/src/ast.cc
File src/ast.cc (right):

http://codereview.chromium.org/7887038/diff/1/src/ast.cc#newcode532
src/ast.cc:532: return !var()->IsLookupSlot();
I'd prefer to keep this a whitelist, listing the things that we can support. 
It's too risky that someone will add a new kind of thing that becomes inlinable
without supporting it.