RFR: 8336685: Shenandoah: Remove experimental incremental update mode [v2]

[William Kemper]

> We've reason to believe that this mode is very rarely used and its maintenance has become a burden for future development.
> 
> ## Testing
> * hotspot_gc_shenandoah
> * dacapo
> * diluvian
> * extremem
> * hyperalloc
> * specjbb2015
> * specjvm2008

William Kemper has updated the pull request incrementally with one additional commit since the last revision:

  Remove unintentional new line

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20316/files
  - new: https://git.openjdk.org/jdk/pull/20316/files/41a2deb8..ec2d6b64

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20316&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20316&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/20316.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20316/head:pull/20316

PR: https://git.openjdk.org/jdk/pull/20316