[llvm] [EarlyCSE] Support CSE for commutative intrinsics with over 2 args (PR #67255)

[via llvm-commits]

XChy wrote:

> I think this is missing a (negative) test where something other than the first two operands are commuted. E.g. fma(a, b, c) and fma(a, c, b).

Thanks for your comment. Negative tests have been added now.

https://github.com/llvm/llvm-project/pull/67255