RFR: 8295868: 32-bit Windows build failures after JDK-8294466

[Aleksey Shipilev]

Fails like this:


* For target support_native_java.desktop_libsplashscreen_splashscreen_impl.obj:
splashscreen_impl.c
c:\buildbot\worker\build-jdkx-windows\build\src\java.desktop\share\native\libsplashscreen\splashscreen_impl.c(443): error C2220: the following warning is treated as an error
c:\buildbot\worker\build-jdkx-windows\build\src\java.desktop\share\native\libsplashscreen\splashscreen_impl.c(443): warning C4018: '>': signed/unsigned mismatch
c:\buildbot\worker\build-jdkx-windows\build\src\java.desktop\share\native\libsplashscreen\splashscreen_impl.c(444): warning C4018: '>': signed/unsigned mismatch
c:\buildbot\worker\build-jdkx-windows\build\src\java.desktop\share\native\libsplashscreen\splashscreen_impl.c(466): warning C4018: '>': signed/unsigned mismatch
c:\buildbot\worker\build-jdkx-windows\build\src\java.desktop\share\native\libsplashscreen\splashscreen_impl.c(467): warning C4018: '>': signed/unsigned mismatch
``` 

I just added the disabled warning for that file. 

Additional testing:
 - [x] Windows x86_32 release (now builds)
 - [ ] Windows x86_32 fastdebug (now builds)
 - [ ] Windows x86_32 slowdebug (now builds)

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

Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/10848/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10848&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8295868
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10848.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10848/head:pull/10848

PR: https://git.openjdk.org/jdk/pull/10848