Refuse to load "literals" that can be confused with registers

The 's' operand overloads the tags for pids and ports to represent
X and Y registers, respectively.  At load time, refuse to load the
module if the "literal" term is not a pid or port, as it would be
interpreted as a register.

This does not happen with normally compiled code, but it can happen
if the compiler (or beam_asm) is abused like in the following example:

make_bad() ->
    Pid = self(),
    Forms = [{attribute, 0, module, bad_s_operand},
             {attribute, 0, export, [{test, 0}]},
             {function, 0, test, 0,
              [{clause, 0, [], [],
                [{call,0,{atom,0,tuple_size},[{integer, 0, Pid}]}]}]}],
    {ok, Module, Bin} = compile:forms(Forms, [no_copt,no_postopt,report_errors]),
    code:load_binary(Module, "bad_s_operand.erl", Bin).

With this commit applied, the following message will be printed
when make_bad() is run:

=ERROR REPORT==== 10-Nov-2017::14:47:59 ===
Loading of bad_s_operand.erl failed: badfile

=ERROR REPORT==== 10-Nov-2017::14:47:59 ===
beam/beam_load.c(2396): Error loading function bad_s_operand:test/0: op bif1_body: bsd:
  the term '<0.60.0>' would be confused with a register

0 files changed, 0 insertions, 0 deletions