RFR: JDK-8253239: Disable VS warning C4307

[Matthias Baesken]

hello, this fixes the build when using VS2017. VS2019 does not have the issue as far as I know.
failure was

> ./test/hotspot/gtest/utilities/test_align.cpp(96): error C2220: warning treated as error - no 'object' file generated
> ./test/hotspot/gtest/utilities/test_align.cpp(156): note: see reference to function template instantiation 'void
> static_test_alignments<T,A>(void)' being compiled with
> [
> T=int64_t,
> A=uint8_t
> ]
> ./test/hotspot/gtest/utilities/test_align.cpp(162): note: see reference to function template instantiation 'void
> test_alignments<int64_t,uint8_t>(void)' being compiled ./test/hotspot/gtest/utilities/test_align.cpp(96): warning
> C4307: '+': integral constant overflow
>
>

This might be related to an issue fixed at least in some versions of VS2019 , that is discussed here :

https://developercommunity.visualstudio.com/content/problem/211134/unsigned-integer-overflows-in-constexpr-functionsa.html

https://bugs.openjdk.java.net/browse/JDK-8253239

-------------

Commit messages:
 - JDK-8253239

Changes: https://git.openjdk.java.net/jdk/pull/237/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=237&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253239
  Stats: 3 lines in 1 file changed: 3 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/237.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/237/head:pull/237

PR: https://git.openjdk.java.net/jdk/pull/237