message: Adding code to AutoGraph that copies the origin_info of an If node to all of the generated nodes. This makes the source mapping properly map all of the lines in the generated functions map back to the original if statement.
diff: @@ -177,6 +177,7 @@ class ControlFlowTransformer(converter.Base):
  orelse_scope = anno.getanno(node, annos.NodeAnno.ORELSE_SCOPE)
  defined_in = anno.getanno(node, anno.Static.DEFINED_VARS_IN)
  live_out = anno.getanno(node, anno.Static.LIVE_VARS_OUT)
  + origin_info = anno.getanno(node, anno.Basic.ORIGIN, default=None)
  # Note: this information needs to be extracted before the body conversion
  # that happens in the call to generic_visit below, because the conversion
  @@ -291,8 +292,13 @@ class ControlFlowTransformer(converter.Base):
  orelse_name, state_getter_name,
  state_setter_name)
  - return (undefined_assigns + cond_assign + composite_defs + body_def +
  + # TODO(b/129493607): investigate how to generalize copying origin
  + # information to all cases where we make new nodes.
  + if_ast = (undefined_assigns + cond_assign + composite_defs + body_def +
  orelse_def + cond_expr)
  + for node in if_ast:
  + anno.setanno(node, anno.Basic.ORIGIN, origin_info)
  + return if_ast
  def _get_loop_state(self, node):
  body_scope = anno.getanno(node, annos.NodeAnno.BODY_SCOPE)
  