The JVM currently runs into Unimplemented() when using -XX:-UseInlineCaches in C2 code (postalloc_expand_java_dynamic_call_sched).
This should get fixed because it's a product flag and it may be helpful as workaround for inline cache related issues.
C2 needs to determine the node size for that, but MacroAssembler::instr_size_for_decode_klass_not_null() is currently broken and should get fixed, too.