Generalize the SDOperand->SDOperand form of  SelectionDAG::ReplaceAllUsesWith to handle replacement of an SDOperand with *any* sdoperand, not just one for a node with a single result.  Note that this has a horrible FIXME'd hack in it to work around PR1975.  This should be removed when PR1975 is fixed.
Generalize the SDOperand->SDOperand form of 
SelectionDAG::ReplaceAllUsesWith to handle replacement of
an SDOperand with *any* sdoperand, not just one for a node with
a single result.  Note that this has a horrible FIXME'd hack in it
to work around PR1975.  This should be removed when PR1975 is fixed.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@46674 91177308-0d34-0410-b5e6-96231b3b80d8

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