Refactor the cast binding to an enum, which clearly enumerates all supported conversions.
This also fixes a bug where `java/foreign/normalize/TestNormalize` was failing when running in interpreted mode (`-Djdk.internal.foreign.DowncallLinker.USE_SPEC=false`), for conversions from `int` to `byte` because the `explicitCast` method handle that was used only considers the least significant bit, while we want to look at all of the least significant byte. As mentioned in the JBS issue, doing this will also make it easier going forward to support multiple conversions with the same from and to types, but requiring different semantics. Testing: jdk_foreign test suite. ------------- Depends on: https://git.openjdk.org/jdk/pull/11019 Commit messages: - Refactor cast operator to enum Changes: https://git.openjdk.org/jdk/pull/11397/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11397&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8297733 Stats: 82 lines in 2 files changed: 56 ins; 14 del; 12 mod Patch: https://git.openjdk.org/jdk/pull/11397.diff Fetch: git fetch https://git.openjdk.org/jdk pull/11397/head:pull/11397 PR: https://git.openjdk.org/jdk/pull/11397
