RFR: 8293329: x86: Improve handling of constants in AES/GHASH stubs [v4]

[Vladimir Ivanov]

> Pre-generating constants saves on startup and static/dynamic footprint a bit, plus simplifies bootstrapping logic. 
> 
> As a downside, constants aren't guaranteed to be always reachable anymore, but since they are used from stubs, finding a scratch register when needed is not a problem.
> 
> Testing: 
> - [x] hs-tier1 - hs-tier4 w/ `-XX:+ForceUnreachable` 
> - [x] x86_32 build

Vladimir Ivanov has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 13 commits:

 - Merge branch 'master' into stub.x86_64.aes.consts
 - Merge branch 'stub.x86_64.aes' into stub.x86_64.aes.consts
 - include
 - Merge branch 'stub.x86_64.aes' into stub.x86_64.aes.consts
 - Merge branch 'master' into stub.x86_64.aes
 - constants
 - Merge branch 'master' into stub.x86_64.aes
 - AESBlockSize
 - update
 - Refactor AES and GHASH stubs.
 - ... and 3 more: https://git.openjdk.org/jdk/compare/30d4145e...a603f29e

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

Changes: https://git.openjdk.org/jdk/pull/10152/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10152&range=03
  Stats: 508 lines in 6 files changed: 151 ins; 233 del; 124 mod
  Patch: https://git.openjdk.org/jdk/pull/10152.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10152/head:pull/10152

PR: https://git.openjdk.org/jdk/pull/10152