The HotSpot JIT is an impressive feat of compiler engineering. The advanced optimisations it performs cannot practically be performed in hardware.

Modern CPUs are capable of, for instance, loop-detection, but they haven't put optimising compilers out of a job, and never will.

Jazelle would add no value on a modern ARM server, for instance. You'd get far better performance out of HotSpot, or some other modern JVM.