RFR: 8320069: RISC-V: Add Zcb instructions [v5]

[Robbin Ehn]

> Hi, this is the instructions for zcb.
> 
> Due to over lack of infrastructure having multiple extension dependent instruction does not fit well.
> Some of these compressed instructions are also missing 1 to 1 mapping, e.g. now we have a compressed not, but the corresponding instruction in uncompressed is still xor.
> I think we need to do some rework here.
> 
> I also I don't like the macro expansion as it hopeless in debugger and 'IDE's (vim+rtags for me).
> (macro stuff was originally done when templates where blacklisted in hotspot)
> 
> And I don't want an option for this, as zcb is coming in hwprobe, if you have compressed on you get them if they are supported (may depend on e.g. zbb).
> 
> I have done some modification since it passed tier1, so I'm running stuff over the weekend.

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

  Review fixes

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17122/files
  - new: https://git.openjdk.org/jdk/pull/17122/files/c30caa0e..f677ca34

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17122&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17122&range=03-04

  Stats: 7 lines in 2 files changed: 0 ins; 2 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/17122.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17122/head:pull/17122

PR: https://git.openjdk.org/jdk/pull/17122