[bugfix] picrin evaluates exprs in files in order.
no need to control arena_index in pic_codegen
cleanup etc/tak.scm
remove toplevel pic_env that is never used
[bugfix] allocate pic_env values area for local variables
fix grammatical error
GC_STRESS default off
s/num_val/valuec/g
s/cv_tbl/dirty_flags/g
reduce allocation size when creating pic_env object in OP_CALL
do not create pic_env object when not needed
add benchmark log notes to tak.scm
add memq/assq
add vector primitives
[bugfix] crash on calling vector-ref
rename pic_code.u.c -> pic_code.u.r
initial char support
initial bytevector support
add some bytevector primitives
add `make tak` command for benchmark