RFR(M) 8176100: [REDO][REDO] G1 Needs pre barrier on dereference of weak JNI handles

[Thomas Schatzl]

Hi Mikael,

On Tue, 2017-03-14 at 14:11 +0100, Mikael Gerdin wrote:
> Here we go again...
> This time around the fix is exactly the same but since I changed the 
> lock ranks in 8176363 we shouldn't be hitting any lock ordering
> assertions.

  (still) looks good to me.

As discussed privately, please wait for the current test runs to
complete before pushing to minimize the risk for a [REDO]^3.

Thanks,
  Thomas