Allow -l option to ocamlmklib on MSVC ports (#1189)

Changes

@@ -147,6 +147,9 @@ Working version
   a trailing "Error: Some fatal warnings were triggered" message.
   (Valentin Gatien-Baron, review by Alain Frisch)
 
+* GPR#1189: allow MSVC ports to use -l option in ocamlmklib
+  (David Allsopp)
+
 ### Manual and documentation:
 
 - MPR#6548: remove obsolete limitation in the description of private

tools/ocamlmklib.ml

@@ -101,6 +101,12 @@ let parse_arguments argv =
     else if s = "-linkall" then
       caml_opts := s :: !caml_opts
     else if starts_with s "-l" then
+      let s =
+        if Config.ccomp_type = "msvc" then
+          String.sub s 2 (String.length s - 2) ^ ".lib"
+        else
+          s
+      in
       c_libs := s :: !c_libs
     else if starts_with s "-L" then
      (c_Lopts := s :: !c_Lopts;