Change legalizeop of FP_ROUND and FP_EXTEND  to not fall through into the ANY_EXTEND/ZERO_EXTEND/SIGN_EXTEND code to simplify it.
Change legalizeop of FP_ROUND and FP_EXTEND  to not fall through
into the ANY_EXTEND/ZERO_EXTEND/SIGN_EXTEND code to simplify it.

Unmerge the code for FP_ROUND and FP_EXTEND from each other to 
make each one simpler.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@46061 91177308-0d34-0410-b5e6-96231b3b80d8

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