RFR: 8324646: Avoid Class.forName in SecureRandom constructor

[Oli Gillespie]

Avoid expensive `Class.forName` call when constructing Providers such as `SecureRandom` which take constructor parameters. This can easily be cached in EngineDescription (this cache already existed before, it was removed in [JDK-8280970](https://bugs.openjdk.org/browse/JDK-8280970) as unused, I'm bringing it back unchanged to support this new usage).

Benchmark results on my Linux x86 host show around a 20% reduction in time to create a new `SecureRandom` instance. Most of the remaining overhead is due to a failing constructor lookup - see [JDK-8324648](https://bugs.openjdk.org/browse/JDK-8324648).


Before
SecureRandomBench.newSecureRandom  avgt   2930 +- 50  ns/op

After
SecureRandomBench.newSecureRandom  avgt   15  2400 +- 33  ns/op


I have seen multiple real-world applications which call `new SecureRandom()` on the hot path, so I believe efficiency here is important.

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

Commit messages:
 - 8324646 - Avoid Class.forName in SecureRandom constructor

Changes: https://git.openjdk.org/jdk/pull/17559/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17559&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8324646
  Stats: 30 lines in 2 files changed: 29 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17559.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17559/head:pull/17559

PR: https://git.openjdk.org/jdk/pull/17559