Fix a bug in DAGcombiner about zero-extend after setcc.

For AArch64 backend, if DAGCombiner see "sext(setcc)", it will
combine them together to a single setcc with extended value type.
Then if it see "zext(setcc)", it assumes setcc is Vxi1, and try to
create "(and (vsetcc), (1, 1, ...)". While setcc isn't Vxi1,
DAGcombiner will create wrong node and get wrong code emitted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198190 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64]Can't select shift left 0 of type v1i64


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198192 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64]Add code to spill/fill Q register tuples such as QPair/QTriple/QQuad.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198193 91177308-0d34-0410-b5e6-96231b3b80d8
For AArch64 Neon, simplify scalar dup by lane0 for fp.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198194 91177308-0d34-0410-b5e6-96231b3b80d8