Make some operator bools explicit for sanity/safety.

There are a couple left in bool-like containers (BitVector, etc) where
the implicit conversions seem more suitable - though it might be worth
considering explicitifying those too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291694 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed