[llvm] [LowerAllowCheck] Rename removeUbsanTrap() to lowerAllowCheck() (PR #149847)

[Marco Elver via llvm-commits]

melver wrote:

While reading this code I got confused why it says "removeUbsanTraps" - I think it should be renamed at this point.

https://github.com/llvm/llvm-project/pull/149847