-Wmissing-braces when compiling with Clang for MINGW

[JPeterMugaas]

While compiling the test suite at https://github.com/walbourn/directxmathtest with Clang 17.0.6, I got some warnings about "suggest braces around initialization of subobject" (-Wmissing-braces).

[4/46] Building CXX object Tests/CMakeFiles/testavx.dir/ext/testavx.cpp.obj
In file included from C:/msys64/home/jpmugaas/directxmath-PKGBUILD/src/directxmath-dec2022/Tests/ext/testavx.cpp:12:
C:/msys64/home/jpmugaas/directxmath-PKGBUILD/src/directxmath-dec2022/Tests/../Extensions/DirectXMathAVX.h:147:17: warning: suggest braces around initialization of subobject [-Wmissing-braces]
  147 |                 WhichX ? 0xFFFFFFFF : 0,
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~
      |                 {
  148 |                 WhichY ? 0xFFFFFFFF : 0,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~
  149 |                 WhichZ ? 0xFFFFFFFF : 0,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~
  150 |                 WhichW ? 0xFFFFFFFF : 0,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~
      |                                        }
1 warning generated.
[6/46] Building CXX object Tests/CMakeFiles/testavx2.dir/ext/testavx2.cpp.obj
In file included from C:/msys64/home/jpmugaas/directxmath-PKGBUILD/src/directxmath-dec2022/Tests/ext/testavx2.cpp:12:
C:/msys64/home/jpmugaas/directxmath-PKGBUILD/src/directxmath-dec2022/Tests/../Extensions/DirectXMathAVX2.h:491:17: warning: suggest braces around initialization of subobject [-Wmissing-braces]
  491 |                 WhichX ? 0xFFFFFFFF : 0,
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~
      |                 {
  492 |                 WhichY ? 0xFFFFFFFF : 0,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~
  493 |                 WhichZ ? 0xFFFFFFFF : 0,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~
  494 |                 WhichW ? 0xFFFFFFFF : 0,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~
      |                                        }