[llvm] [M68k] always use movem for register spills (PR #106715)

[via llvm-commits]

0x59616e wrote:

Thanks for this fix! I have one question: How can we ensure that our test targets the exact issue we're trying to address?

To be more specific, we are addressing two issues: spill instruction & spill size, and I don't know how these two issues are being targeted with the [llvm/test/CodeGen/M68k/PR57660.ll](https://github.com/llvm/llvm-project/pull/106715/files#diff-b49525188447bfeaedab9d052d669840b4d5edce05824f657175dba5c65003c0).

It would be great if you could give more details or add a new test. Thanks!

https://github.com/llvm/llvm-project/pull/106715