[ubsan] Mark a test case as unsupported on Windows
[ubsan] Mark a test case as unsupported on Windows

__ubsan_on_report isn't defined as weak, and redefining it in a test is
not supported on Windows.

See the error message here: https://reviews.llvm.org/D48446

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@335523 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt