In dag-optnone.ll, use varargs instead of win64 to fast SDIsel.
In dag-optnone.ll, use varargs instead of win64 to fast SDIsel.

The test used to rely on targeting win64 to disable fast isel,
but I'd like to teach fast isel about win64 rets.  Change the
test to use varargs to disable fast isel.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@275568 91177308-0d34-0410-b5e6-96231b3b80d8

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