[ConstantInt] Use ConstantInt::getValue instead of Constant::getUniqueInteger in a few places where we obviously have a ConstantInt. NFC

getUniqueInteger will ultimately call ConstantInt::getValue, but calling ConstantInt::getValue should be inlined.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310069 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed