Remove explicit RNSuccIterator copy assignment in favor of implicit default
Remove explicit RNSuccIterator copy assignment in favor of implicit default

Asserting that the source and destination iterators are from the same
region is unnecessary - there's no reason to disallow reassignment from
any regions, so long as they aren't compared.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@231224 91177308-0d34-0410-b5e6-96231b3b80d8

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