RFR: Rename BrooksPointer to ShenandoahBrooksPointer

[Roman Kennke]

Ok

Am 9. November 2018 23:11:53 MEZ schrieb Aleksey Shipilev <shade at redhat.com>:
>http://cr.openjdk.java.net/~shade/shenandoah/rename-brooksptr/webrev.01/
>
>There is the convention to have Shenandoah-specific files and types to
>have "Shenandoah" in their
>names. This changeset renames the major offender to that rule:
>BrooksPointer.
>
>Testing: {x86_64, aarch64} builds, tier1_gc_shenandoah
>
>Thanks,
>-Aleksey