anchor.diff:      Ls.
   
   -spec rename_vars(Rename, [label()], block_map()) -> block_map() when
  -      Rename :: [{var_name(),value()}] | #{var_name():=value()}.
  +      Rename :: rename_map() | rename_proplist().
   
   rename_vars(Rename, From, Blocks) when is_list(Rename) ->
       rename_vars(maps:from_list(Rename), From, Blocks);
  
positive.code: %% Purpose: Type definitions and utilities for the SSA format.
  
  -module(beam_ssa).
  -export([add_anno/3,get_anno/2,
           clobbers_xregs/1,def/2,def_used/2,dominators/1,
           flatmapfold_instrs_rpo/4,
           fold_po/3,fold_po/4,fold_rpo/3,fold_rpo/4,
           fold_instrs_rpo/4,
           linearize/1,
           mapfold_instrs_rpo/4,
           normalize/1,
           no_side_effect/1,
  
negative.code: -type b_switch()   :: #b_switch{}.
  -type terminator() :: b_br() | b_ret() | b_switch().
  
  -type construct()  :: b_module() | b_function() | b_blk() | b_set() |
                        terminator().
  
  -type b_var()      :: #b_var{}.
  -type b_literal()  :: #b_literal{}.
  -type b_remote()   :: #b_remote{}.
  