LLVM Swift Compilation remove unused parameters

Is it possible for LLVM to remove unused parameters in precompilation? For example:

// Non compiled code
func doSomething(a: Int, b: Int) { // "b" is unused
  compute(a)
}

Compile to something equal to this code:

// Expected compiled code
func doSomething(a: Int) {
  compute(a)
}