MathExtras UnitTest: Assert that isPowerOf2(0) is false. NFC.
MathExtras UnitTest: Assert that isPowerOf2(0) is false. NFC.

Summary:
This is a follow-up on D34077. Elena observed that the
correctness of the code relies on isPowerOf2(0) returning false.
Adding a test to cover this corner-case.

Reviewers: delena, davide, craig.topper

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34939

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@307046 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm