[dsymutil] Ensure we're comparing time stamps with the same precision.

After TimePoint's precision was increased in LLVM we started seeing
failures because the modification times didn't match. This adds a time
cast to ensure that we're comparing TimePoints with the same amount of
precision.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348283 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed