flambda-backend: Revert ocaml/driver/ changes that are duplicative

Author: mshinwell

driver/main_args.ml

@@ -966,9 +966,6 @@ let mk_afl_inst_ratio f =
   \     (advanced, see afl-fuzz docs for AFL_INST_RATIO)"
 ;;
 
-let mk_alloc_check f =
-  "-zero-alloc-check", Arg.Unit f, "<ignored>"
-
 let mk__ f =
   "-", Arg.String f,
   "<file>  Treat <file> as a file name (even if it starts with `-')"
@@ -1204,7 +1201,6 @@ module type Optcomp_options = sig
   val _save_ir_after : string -> unit
   val _probes : unit -> unit
   val _no_probes : unit -> unit
-  val _alloc_check : unit -> unit
 end;;
 
 module type Opttop_options = sig
@@ -1582,7 +1578,6 @@ struct
     mk_dump_into_file F._dump_into_file;
     mk_dump_dir F._dump_dir;
     mk_dump_pass F._dump_pass;
-    mk_alloc_check F._alloc_check;
 
     mk_args F._args;
     mk_args0 F._args0;
@@ -2074,7 +2069,6 @@ module Default = struct
     let _v () = Compenv.print_version_and_library "native-code compiler"
     let _no_probes = clear probes
     let _probes = set probes
-    let _alloc_check () = ()
   end
 
   module Odoc_args = struct

driver/main_args.mli

@@ -246,7 +246,6 @@ module type Optcomp_options = sig
   val _save_ir_after : string -> unit
   val _probes : unit -> unit
   val _no_probes : unit -> unit
-  val _alloc_check : unit -> unit
 end;;
 
 module type Opttop_options = sig