After JDK-8245464, we have this shape of cset check:

  ...65: mov %rax,%r10
  ...68: shr $0x17,%r10
  ...6c: mov $0x10000,%r11d
  ...72: cmpb $0x0,(%r11,%r10,1)
  ...77: je 0x00007f868c8ef355

But the immediate is very small, so there is no reason why it should take %r11. If we massage the code a bit with:
  https://cr.openjdk.java.net/~shade/8245465/webrev.02/

  ...e5: mov %rax,%r10
  ...e8: shr $0x17,%r10
  ...ec: cmpb $0x0,0x10000(%r10)
  ...f4: je 0x00007f6be48f7ed5

Then we save the register there, and LRB midpath is also 3 bytes more compact.