Actually remove insert_bb

kani-compiler/src/kani_middle/transform/body.rs

@@ -322,31 +322,6 @@ impl MutableBody {
  };
  }
 
- /// Insert basic block before or after the source instruction and update `source` accordingly. If
- /// `InsertPosition` is `InsertPosition::Before`, `source` will point to the same instruction as
- /// before. If `InsertPosition` is `InsertPosition::After`, `source` will point to the
- /// terminator of the newly inserted basic block.
- pub fn insert_bb(
- &mut self,
- mut bb: BasicBlock,
- source: &mut SourceInstruction,
- position: InsertPosition,
- ) {
- // Splitting adds 1 block, so the added block index is len + 1;
- let split_bb_idx = self.blocks().len();
- let inserted_bb_idx = self.blocks().len() + 1;
- // Update the terminator of the basic block to point at the remaining part of the split
- // basic block.
- let target = get_mut_target_ref(&mut bb.terminator);
- *target = split_bb_idx;
- let new_term = Terminator {
- kind: TerminatorKind::Goto { target: inserted_bb_idx },
- span: source.span(&self.blocks),
- };
- self.split_bb(source, position, new_term);
- self.blocks.push(bb);
- }
-
  pub fn insert_terminator(
  &mut self,
  source: &mut SourceInstruction,