RFR: 8202082: Remove explicit CMS checks in CardTableBarrierSetAssembler

[Aleksey Shipilev]

On 04/23/2018 12:00 PM, Erik Österlund wrote:
> You are right, the previous code has been inconsistent. Sometimes it checked just for CMS, and
> sometimes CMS + pre-cleaning. The actual property we are looking for is whether the card table is
> scanned concurrently or not (which I want to determine at a single place instead of all over the
> place). And for CMS, this is only when pre-cleaning is enabled. The callsites that only checked for
> CMS (and not CMS + pre-cleaning) are fencing despite there being no actual race to protect against.

Yup, that's what I wanted to be confirmed.

Looks good.

-Aleksey