Fix pattern match for movi with 0D result

Patch by Jiangning Liu.

With some test case changes:
- intrinsic test added to the existing /test/CodeGen/AArch64/neon-aba-abd.ll.
- New test cases to cover movi 1D scenario without using the intrinsic in
test/CodeGen/AArch64/neon-mov.ll.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196806 91177308-0d34-0410-b5e6-96231b3b80d8
Don't set a variable to its default value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196807 91177308-0d34-0410-b5e6-96231b3b80d8