ARM & AArch64: unify the rest of the completely shared NEON implementations
ARM & AArch64: unify the rest of the completely shared NEON implementations

This should be the last routine patch: AArch64 does still delegate to
EmitARMBuiltinExpr, but the remaining instances have complications of
one sort or another so some more cunning thought will be needed.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@200528 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang