[SelectionDAG] Update check in createOperands to reflect max() is a valid value.
[SelectionDAG] Update check in createOperands to reflect max() is a valid value.

The value returned by max() is the last valid value, adjust the
comparison accordingly.

The code added in D55073 creates TokenFactors with max() operands.

Reviewers: aemerson, efriedma, RKSimon, craig.topper

Reviewed By: aemerson

Differential Revision: https://reviews.llvm.org/D56738

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@351318 91177308-0d34-0410-b5e6-96231b3b80d8

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