RFR: 8201647: Make initial clearing of CHeapBitMap optional

[Stuart Monteith]

Not that I'm a reviewer, but that looks good to me.

On 17 April 2018 at 13:38, Per Liden <per.liden at oracle.com> wrote:
> CHeapBitMap objects will by default clear the underlying bitmap during
> construction. In ZGC we don't want mark bitmaps to be cleared on
> construction, since we instead do this lazily during concurrent marking.
>
> This patch adds a "bool clear = true" argument to CHeapBitMap's constructor
> to be able to opt-out of this behavior.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8201647
> Webrev: http://cr.openjdk.java.net/~pliden/8201647/webrev.0
>
> /Per