darray was used in YJIT which required the functions to not trigger GC.
YJIT has now moved to Rust and does not use darray anymore, so we can
remove the functions that don't trigger GC and only keep the ones that
trigger GC.
Using a fake (malloc) RArray is not friendly for the garbage
collector. Fake RArray does not have a heap page, so it causes Variable
Width Allocation to crash when we try to implement it on Arrays.
This commit changes feature_index from a RArray to a darray.
* Tie lifetime of uJIT blocks to iseqs
Blocks weren't being freed when iseqs are collected.
* Add rb_dary. Use it for method dependency table
* Keep track of blocks per iseq
Remove global version_tbl
* Block version bookkeeping fix
* dary -> darray
* free ujit_blocks
* comment about size of ujit_blocks