In preparation of #8855 this PR refactors the conversions from `List` to array and array to `List`, reducing the number of conversions when calling `MethodHandles.dropArguments` in particular. This remove about ~5% of allocations on the `StringConcatFactoryBootstraps` microbenchmark.
------------- Commit messages: - Move all conversions closer to the edge - Merge master - Streamline MHs.dropArguments parameter handling - Missed correctly taking b1 into account in of(byte, int, int...) (java/lang/String/concat/ImplicitStringConcatShapes.java test failure) - Address review comments, fix unsafe shift, rework and remove ofBothArrays - Revert unrelated and unverified hashCode change - Improve TransformKey to pack more kinds of transforms efficiently Changes: https://git.openjdk.java.net/jdk/pull/8923/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8923&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8287442 Stats: 46 lines in 3 files changed: 9 ins; 3 del; 34 mod Patch: https://git.openjdk.java.net/jdk/pull/8923.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/8923/head:pull/8923 PR: https://git.openjdk.java.net/jdk/pull/8923
