RFR: 8301820: C4819 warnings were reported on Windows

[Yasumasa Suenaga]

C4819 warnings were reported when I tried to build JDK on Windows with VS2022.
This PR contains changes both HotSpot and client libraries. Let me know if they should be separated.

* HotSpot
    * stubGenerator_x86_64_poly.cpp
    * elfFile.hpp
* libfontmanager
    * hb.hh
* libfreetype
    * afblue.c

I added C4819 to `DISABLED_WARNINGS_microsoft` for libfontmanager and for libfreetype because they are 3rd-party libraries.

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Commit messages:
 - 8301820: C4819 warnings were reported on Windows

Changes: https://git.openjdk.org/jdk/pull/12427/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12427&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8301820
  Stats: 56 lines in 3 files changed: 0 ins; 0 del; 56 mod
  Patch: https://git.openjdk.org/jdk/pull/12427.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12427/head:pull/12427

PR: https://git.openjdk.org/jdk/pull/12427