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

[Daniel Jeliński]

On Mon, 17 Jul 2023 18:31:41 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

> 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.

Mach5 came back clean. Thanks for the reviews!

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PR Comment: https://git.openjdk.org/jdk/pull/14907#issuecomment-1641592344