RFR: 8300237: Minor improvements in MethodHandles [v4]

[Sergey Tsypanov]

> - `MethodType.ptypes()` can be used instead of `MethodType.parameterList()` when we don't need a copy
> - comparison of two lists can be done without `Stream.reduce()`

Sergey Tsypanov has updated the pull request incrementally with one additional commit since the last revision:

  Merge map() calls

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12025/files
  - new: https://git.openjdk.org/jdk/pull/12025/files/cab00aee..f3fc18dc

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12025&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12025&range=02-03

  Stats: 10 lines in 1 file changed: 7 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/12025.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12025/head:pull/12025

PR: https://git.openjdk.org/jdk/pull/12025