refactor: read the .cmt earlier

Author: Bushuo

compiler/gentype/GenTypeMain.ml

@@ -142,25 +142,25 @@ let process_cmt_file cmt =
     let output_file_relative = cmt |> Paths.get_output_file_relative ~config in
     let file_name = cmt |> Paths.get_module_name in
     let is_interface = Filename.check_suffix cmt_file ".cmti" in
+    let input_cmt, has_gentype_annotations =
+      read_input_cmt is_interface cmt_file
+    in
+    let source_file =
+      match input_cmt.cmt_annots |> FindSourceFile.cmt with
+      | Some source_file -> source_file
+      | None -> (
+        (file_name |> ModuleName.to_string)
+        ^
+        match is_interface with
+        | true -> ".resi"
+        | false -> ".res")
+    in
     let resolver =
       ModuleResolver.create_lazy_resolver ~config
         ~extensions:[".res"; ".shim.ts"] ~exclude_file:(fun fname ->
           fname = "React.res" || fname = "ReasonReact.res")
     in
-    let input_cmt, has_gentype_annotations =
-      read_input_cmt is_interface cmt_file
-    in
     if has_gentype_annotations then
-      let source_file =
-        match input_cmt.cmt_annots |> FindSourceFile.cmt with
-        | Some source_file -> source_file
-        | None -> (
-          (file_name |> ModuleName.to_string)
-          ^
-          match is_interface with
-          | true -> ".resi"
-          | false -> ".res")
-      in
       input_cmt
       |> translate_c_m_t ~config ~output_file_relative ~resolver
       |> emit_translation ~config ~file_name ~output_file ~output_file_relative