Revert "[java] no longer catching Class_structure_exception"

Summary:public
Revert 6fa9b995e5 (D2843010).

It's slightly less worse to silently ignore Java8 rather than crashing. We'll
wait for an upstream fix to Javalib to resolve the issue of leaked file
descriptors that the original diff was trying to address.

Reviewed By: sblackshear

Differential Revision: D3040978

fb-gh-sync-id: 4020221
shipit-source-id: 4020221

infer/src/java/jClasspath.ml

@@ -176,6 +176,7 @@ let load_sources_and_classes () =
       | JVerbose.Classpath parsed_paths ->
           loop parsed_paths roots sources classes
     with
+    | JBasics.Class_structure_error _
     | Parsing.Parse_error
     | Invalid_argument _
     | Failure "lexing: empty token" -> loop paths roots sources classes
@@ -255,9 +256,11 @@ let collect_classes classmap jar_filename =
   let classpath = Javalib.class_path jar_filename in
   let collect classmap cn =
     JBasics.ClassMap.add cn (Javalib.get_class classpath cn) classmap in
+  try
     let classes = IList.fold_left collect classmap (extract_classnames [] jar_filename) in
     Javalib.close_class_path classpath;
     classes
+  with JBasics.Class_structure_error _ -> classmap
 
 
 let load_program classpath classes =