[llvm] [ScalarEvolution] Limit recursion in getRangeRef for PHI nodes. (PR #152823)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

> Example testcase:
> llvm-test-suite/SingleSource/Regression/C/gcc-c-torture/execute/pr68249.c

This is subtly different: the other one is a PHI which depends on another PHI, this is a PHI which depends on itself.  We can also handle this, I think, but the handling looks a bit different.

https://github.com/llvm/llvm-project/pull/152823