isKnownToBeAPowerOfTwo: (X & Y) + Y is a power of 2 or zero if y is also.

This is useful if something that looks like (x & (1 << y)) ? 64 : 32 is
the divisor in a modulo operation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182200 91177308-0d34-0410-b5e6-96231b3b80d8
Unsupported remote JIT on ARM

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182201 91177308-0d34-0410-b5e6-96231b3b80d8