Revert "PR#6475: accept -o in ocamlc when compiling C files"

This reverts commit 1d8e590c54.

Conflicts:
	Changes
	bytecomp/bytelink.ml
	driver/optcompile.ml
	ocamlbuild/ocaml_specific.ml
	ocamlbuild/testsuite/internal.ml
	utils/ccomp.ml

bytecomp/bytelink.ml

@@ -593,7 +593,7 @@ let link ppf objfiles output_name =
       link_bytecode_as_c ppf tolink c_file;
       if not (Filename.check_suffix output_name ".c") then begin
         temps := c_file :: !temps;
-        if Ccomp.compile_file ~output_name:(Some obj_file) c_file <> 0 then
+        if Ccomp.compile_file c_file <> 0 then
           raise(Error Custom_runtime);
         if not (Filename.check_suffix output_name Config.ext_obj) ||
            !Clflags.output_complete_object then begin

driver/compile.ml

@@ -107,4 +107,4 @@ let implementation ppf sourcefile outputprefix =
 
 let c_file name =
   Location.input_name := name;
-  if Ccomp.compile_file ~output_name:!Clflags.output_name name <> 0 then exit 2
+  if Ccomp.compile_file name <> 0 then exit 2

driver/optcompile.ml

@@ -141,5 +141,4 @@ let implementation ppf sourcefile outputprefix ~backend =
     raise x
 
 let c_file name =
-  let output_name = !Clflags.output_name in
-  if Ccomp.compile_file ~output_name name <> 0 then exit 2
+  if Ccomp.compile_file name <> 0 then exit 2

utils/ccomp.ml

@@ -75,17 +75,13 @@ let compile_file ~output_name name =
   let exit =
     command
       (Printf.sprintf
-         "%s%s -c %s %s %s %s %s%s"
+         "%s -c %s %s %s %s %s%s"
          (match !Clflags.c_compiler with
           | Some cc -> cc
           | None ->
               if !Clflags.native_code
               then Config.native_c_compiler
               else Config.bytecomp_c_compiler)
-         (match output_name, Config.ccomp_type with
-            | Some n, "msvc" -> " /Fo" ^ Filename.quote n
-            | Some n, _ -> " -o " ^ Filename.quote n
-            | None, _ -> "")
          (if !Clflags.debug && Config.ccomp_type <> "msvc" then "-g" else "")
          (String.concat " " (List.rev !Clflags.all_ccopts))
          (quote_prefixed "-I" (List.rev !Clflags.include_dirs))

utils/ccomp.mli

@@ -14,7 +14,7 @@
 
 val command: string -> int
 val run_command: string -> unit
-val compile_file: output_name:string option -> string -> int
+val compile_file: string -> int
 val create_archive: string -> string list -> int
 val expand_libname: string -> string
 val quote_files: string list -> string