[jdk17u-ri] RFR: 8297878: KEM: Implementation [v2]

[Weijun Wang]

> This is the KEM API backport to JDK 17u.
> 
> The `src` files are identical to those in the current `jdk` repo except for the change made to `KEM.java` at https://github.com/openjdk/jdk/commit/59c2aff1edffb66762bbbe5e310913f87953be5b#diff-7bee547996d0de5692181a509bdf509276c7eb9351722580fd6aee7975745e67.
> 
> The `RSA_KEM` code is modified because `DerOutputStream` lacks several methods in JDK 17.
> 
> `Proc` is updated like in JDK 21 to support for some internal interop testing. The test files for `Proc` are also backported.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  use jdk17 style comment

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

Changes:
  - all: https://git.openjdk.org/jdk17u-ri/pull/1/files
  - new: https://git.openjdk.org/jdk17u-ri/pull/1/files/4f9f7dc9..cd4aac2b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk17u-ri&pr=1&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk17u-ri&pr=1&range=00-01

  Stats: 5 lines in 2 files changed: 0 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk17u-ri/pull/1.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-ri.git pull/1/head:pull/1

PR: https://git.openjdk.org/jdk17u-ri/pull/1