RFR: 8253457: Remove unimplemented register stack functions [v2]

[Coleen Phillimore]

> Please review removed functions left over from Itanium.
> 
> Ran tier1 testing on Oracle platforms (linux-x64, macos-x64, windows-x64 and linux-aarch64) and built on
> linux-arm32,linux-ppc64le-debug,linux-s390x-debug,linux-x64-zero.
> Thanks,
> Coleen

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  added back unintentionally deleted functions

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/300/files
  - new: https://git.openjdk.java.net/jdk/pull/300/files/ab9514cc..50d74884

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=300&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=300&range=00-01

  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/300.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/300/head:pull/300

PR: https://git.openjdk.java.net/jdk/pull/300