Attempt to workaround MSVC build issue where I suspect an enum class constant 0 is considered a possible null pointer

I can't reproduce this so far with web compilers, so throwing this at
the bots to see if it sticks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292155 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed