RFR: 8312190: Fix c++11-narrowing warnings in hotspot code

[Daniel Jeliński]

This patch fixes compilation warnings produced by Clang when compiling on Windows.

Clang emulates MSVC behavior and uses `int` for enumeration types that do not explicitly specify the underlying type. This patch sets an explicit underlying type for 3 enumerations to fix the warnings.

See Microsoft's documentation of [Zc:enumTypes](https://learn.microsoft.com/en-us/cpp/build/reference/zc-enumtypes?view=msvc-170) for more information.

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Commit messages:
 - Update copyright
 - Fix clang narrowing warnings

Changes: https://git.openjdk.org/jdk/pull/14907/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14907&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8312190
  Stats: 4 lines in 2 files changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/14907.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14907/head:pull/14907

PR: https://git.openjdk.org/jdk/pull/14907