[llvm] [DA] remove constraint propagation and coupled/separable subscripts (PR #160924)

[Sebastian Pop via llvm-commits]

sebpop wrote:

We rarely (maybe less than 1% of codes) need the Banerjee MIV test if delinearization is enabled.
Overall these patches remove 1900 SLoC and disable MIV another ~200 SLoC.
With these changes, DA is now about 3500 SLoC.

https://github.com/llvm/llvm-project/pull/160924