remove redundant imports

detects redundant imports that can be eliminated.

for #117772 :

In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.

compiler/rustc_codegen_ssa/src/mir/statement.rs

@@ -3,7 +3,6 @@ use rustc_middle::mir::NonDivergingIntrinsic;
 
 use super::FunctionCx;
 use super::LocalRef;
-use crate::traits::BuilderMethods;
 use crate::traits::*;
 
 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {