YJIT: implement cache for recently encoded/decoded contexts (#10938) #659

Job	Run time
make (check, cppflags=-DVM_CHECK_MODE)	9m 2s
make (check, i686)	10m 57s
make (check, --disable-yjit)	7m 44s
make (check, --enable-shared --enable-load-relative)	7m 36s
make (check, --with-shared-gc)	7m 18s
make (test-bundler-parallel)	23m 4s
make (test-bundled-gems)	18m 36s
make (check, ubuntu-20.04)	8m 57s
Ubuntu result	1s
	1h 33m 15s

Provide feedback