[flow] Drop fuzzy_score's dependence on Exception.ml

Summary:
The goal is to make autocomplete work in try-flow.

The dependence pulls in some unix code, which won't work in flow.js. This diff removes it. I don't think we lose much without the exception wrapping.

Changelog: [internal]

Reviewed By: panagosg7

Differential Revision: D55555437

fbshipit-source-id: 5a64cf341c578ad87895c6d9242511a7914b60e8

src/common/fuzzy_score/dune

@@ -1,7 +1,7 @@
 (library
  (name fuzzy_score)
  (wrapped false)
- (libraries base utils_core))
+ (libraries base))
 
 (dirs
  (:standard __tests__))

src/common/fuzzy_score/fuzzy_score.ml

@@ -362,8 +362,8 @@ let fuzzy_score
               fill_columns (column + 1) (word_pos + 1)
           and fill_columns column word_pos =
             try fill_columns_unsafe column word_pos with
-            | Invalid_argument msg as exn ->
-              let exn = Exception.wrap exn in
+            | Invalid_argument msg ->
+              let bt = Printexc.get_raw_backtrace () in
               let msg =
                 Printf.sprintf
                   "%s (pattern: %S, word: %S, row: %d, column: %d)"
@@ -373,7 +373,7 @@ let fuzzy_score
                   row
                   column
               in
-              Exception.raise_with_backtrace (Invalid_argument msg) exn
+              Printexc.raise_with_backtrace (Invalid_argument msg) bt
           in
           let column = fill_columns (min_word_match_pos_ - word_start + 1) min_word_match_pos_ in