[llvm] [GlobaISel] Allow expanding of sdiv -> mul by constant (PR #146504)

[David Green via llvm-commits]

================
@@ -0,0 +1,1585 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
----------------
davemgreen wrote:

Can you move this up a folder. It looks useful for testing sdag as well as gisel.

If you wanted to keep the undef tests, you could replace undef with poison.

https://github.com/llvm/llvm-project/pull/146504