[AArch64] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC).
[AArch64] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309062 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 1778f81efa126dcde36a08ceeb080bfa618f667c)

Only includes AArch64CallLowering.h.

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm