[AArch64][GlobalISel] Support sibling calls with mismatched calling conventions

Add support for sibcalling calls whose calling convention differs from the
caller's.

- Port over `CCState::resultsCombatible` from CallingConvLower.cpp into
  CallLowering. This is used to verify that the way the caller and callee CC
  handle incoming arguments matches up.

- Add `CallLowering::analyzeCallResult`. This is basically a port of
  `CCState::AnalyzeCallResult`, but using `ArgInfo` rather than `ISD::InputArg`.

- Add `AArch64CallLowering::doCallerAndCalleePassArgsTheSameWay`. This checks
  that the calling conventions are compatible, and that the caller and callee
  preserve the same registers.

For testing:

- Update call-translator-tail-call.ll to show that we can now handle this.

- Add a GISel line to tailcall-ccmismatch.ll to show that we will not tail call
  when the regmasks don't line up.

Differential Revision: https://reviews.llvm.org/D67361

llvm-svn: 371570