[AArch64][GlobalISel] Support tail calling with swiftself parameters

[AArch64][GlobalISel] Support tail calling with swiftself parameters

Swiftself uses a callee-saved register. We can tail call when the register used
in the caller and callee is the same.

This behaviour is equivalent to that in `TargetLowering::parametersInCSRMatch`.

Update call-translator-tail-call.ll to verify that we can do this. When we
support inline assembly, we can write a check similar to the one in the
general swiftself.ll. For now, we need to verify that we get the correct COPY
instruction after call lowering.

Differential Revision: https://reviews.llvm.org/D67511

llvm-svn: 371788