introduce int cells to avoid object allocation
intcells are also closure cells, but with possibly only an intvalue
nits
Merge remote-tracking branch 'origin/master' into tim/intcells
update test
Implement Array#assoc and #rassoc
Test for joining a list of path fragments starting with an empty string.
Fix File::join when the first path fragment is an empty string.
Create directories with correct permissions in Dir::mkdir.
Untag assoc_spec and rassoc_spec
Adding support for --version flag

which also involved extracting the common version info parts used later
on for `RUBY_` constants and such.
Using the Ruby space as a memo

instead of passing around/memoizing values from yet another function.  I
*think* this is more in keeping with other parts of topaz, and I hope is
more like what @alex would want :-)
Directly fetching const

rather than spinning up an execution context.  Not happy about the
duplication.  Meh.
Much improved File::join implementation.
Folding the const assignments back into `_entry_point`

since it felt kinda weird and wasn't saving much, but was adding a ton
to the generated C.  I'm still not sure if I should even think about
looking at the generated C...
Using local var directly

now that it's available again.
Protect against recursive arrays in File::join.
No need to import RubyError here.
Merge branch 'master' into jerith/dir-file-fixes
Better dir permissions test.