Remove a test case that no longer makes sense.
Remove a test case that no longer makes sense.

This was testing the handling of sub-register coalescing followed by
remat.  The original problem was caused by the extra <imp-def> operands
added by sub-register coalescing.  Those <imp-def> operands are not
added any longer, and the test case passes even when the original patch
is reverted.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@152040 91177308-0d34-0410-b5e6-96231b3b80d8

GPUOpen-Drivers/llvm,dslab-epfl/asap,GPUOpen-Drivers/llvm,chubbymaggie/asap,chubbymaggie/asap,dslab-epfl/asap,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,apple/swift-llvm,chubbymaggie/asap,apple/swift-llvm,apple/swift-llvm,chubbymaggie/asap,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,chubbymaggie/asap,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,dslab-epfl/asap,apple/swift-llvm,chubbymaggie/asap,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,dslab-epfl/asap,dslab-epfl/asap,GPUOpen-Drivers/llvm,llvm-mirror/llvm