Use ALWAYS_INLINE for vm_getinstancevariable #60

Job	Run time
make (btest, --zjit-call-threshold=2, --enable-zjit=dev)	5m 12s
ruby-bench (--zjit-call-threshold=2, --warmup=1 --bench=1, --enable-zjit=dev_nodebug)	19m 24s
make (check, --zjit-disable-hir-opt --zjit-call-threshold=1, -T --zjit-disable-hir-opt -T --zjit-...	15m 32s
cargo clippy	43s
make (zjit-bindgen, To fix: use patch in logs, --enable-zjit=dev --with-gcc=clang-16, /usr/bin/cl...	4m 50s
make (check, --zjit-call-threshold=1, -T --zjit-call-threshold=1, --enable-zjit=dev)	19m 19s
make (zjit-check, --enable-yjit --enable-zjit=dev, 1.85.0)	4m 48s
make (test-bundled-gems, --enable-zjit=dev, --zjit-call-threshold=1)	21m 23s
ZJIT Ubuntu result	3s
	1h 31m 14s

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