RFR: 8303900: Rename BitMap search functions [v2]

[Kim Barrett]

> Please review this renaming of the following functions in BitMap:
> 
> get_next_one_offset => find_first_set_bit
> get_next_zero_offset => find_first_clear_bit
> get_next_one_offset_aligned_right => find_first_set_bit_aligned_right
> 
> Note that ShenandoahMarkBitMap::get_next_one_offset is not being renamed.  For
> some reason that class contains a copy of a sizable chunk of the code from
> some version of BitMap.  (Not sure why it doesn't use an internal BitMapView
> rather than code copying.)
> 
> Testing:
> mach5 tier1-5

Kim Barrett has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains eight additional commits since the last revision:

 - Merge branch 'master' into find-rename
 - update gtests
 - update shenandoah uses
 - update zgc uses
 - update gc/shared uses
 - update Parallel uses
 - update G1 uses
 - rename functions

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/12951/files
  - new: https://git.openjdk.org/jdk/pull/12951/files/94fa65a5..c503e584

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12951&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12951&range=00-01

  Stats: 63148 lines in 577 files changed: 54630 ins; 2410 del; 6108 mod
  Patch: https://git.openjdk.org/jdk/pull/12951.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12951/head:pull/12951

PR: https://git.openjdk.org/jdk/pull/12951