This reduces crate_ctxt copying (which unfortunately did not
result in a noticeable speedup), and makes the role of that
type a bit more clear.

Not totally confident this is desirable. The alternative would be to make it a
compile error.

Add missing tests

stdlib: Add some vector functions: empty, empty_mut, grow_set, and freeze. Change _vec.grow to use uint arguments.

rustc: Remove the "boxed" check, and make the static_size_of_tag recursion-eliminating transformation deep

rust once the necessary APIs are available in C.

Only works for uints at present. Necessitated the addition of _str.to_upper.

Begin passing an ExtFmt.RT.conv parsed format description to each of the
ExtFmt.RT.conv* functions.

Also did some refactoring in typestate_check. All test cases in
compile-fail that involve uninitialized vars now fail correctly!
(All eight of them, that is.)

Fix temporary-spilling logic in trans_args, uncomment most of lib-deque.rs (which now passes on stage0).