[llvm] [RISCV] Enable TTI::shouldDropLSRSolutionIfLessProfitable by default (PR #89927)

[Alex Bradbury via llvm-commits]

asb wrote:

@dtcxzyw thank you, that's definitely more impact than I was expecting so I've reverted while it's still easy to do so in order to allow proper investigation.

https://github.com/llvm/llvm-project/pull/89927