[libcxx] [test] D27019: Fix MSVC warning C4245 "conversion from 'X' to 'Y', signed/unsigned mismatch", part 6/12.

Add static_cast when initializing unsigned integers with negative numbers (in order to obtain big values).

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@287826 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed