RFR: 8297864: Dead code elimination [v3]

[Robbin Ehn]

> Please consider removing all this dead code.
> I did not have any good way of splitting this up and I did not see any benefit is just splitting it up 'just because'.
> There is one commit per file couple.
> Not much else to say, passes t1-4 and I can build:
> linux-aarch64-debug,linux-arm32-debug,linux-ppc64le-debug,linux-s390x-debug,linux-x86,linux-x86-debug,macosx-aarch64-debug,macosx-x64,macosx-x64-debug,windows-x64-debug,windows-x86-debug and zero-x64-debug
> Some of them I also built release.

Robbin Ehn has updated the pull request incrementally with one additional commit since the last revision:

  Fixed whitespace nit

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11439/files
  - new: https://git.openjdk.org/jdk/pull/11439/files/480495ef..cce07f52

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11439&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11439&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/11439.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11439/head:pull/11439

PR: https://git.openjdk.org/jdk/pull/11439