RFR: 8255449: Improve the exception message of MethodHandles::permuteArguments

[Jorn Vernee]

Hi,

Currently, if MethodHandles::permuteArguments is used with a reorder array that is the wrong size, or one of the indexes in it is out of bounds of the new type, we simply get the exception message:

    bad reorder array [...]

I think we can improve the exception message by splitting these two error cases, and saying in the message exactly what went wrong.

permuteArguments is a tricky API, so improving the error message here should help to improve developer productivity.

This PR proposes splits the error message into e.g.:

    old type parameter count and reorder array length do not match: (int,int,String)int, [0, 0]

For an incorrect reorder array length, and:

    index is out of bounds for new type: 2, (int,String)int

For an out of bounds index.

Thanks,
Jorn

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Commit messages:
 - Improve wording of permuteArguments exception message

Changes: https://git.openjdk.java.net/jdk/pull/878/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=878&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255449
  Stats: 19 lines in 1 file changed: 4 ins; 3 del; 12 mod
  Patch: https://git.openjdk.java.net/jdk/pull/878.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/878/head:pull/878

PR: https://git.openjdk.java.net/jdk/pull/878