Command line option to use the new exception handling instructions

Author: vouillon

compiler/lib-wasm/binaryen.ml

@@ -134,6 +134,7 @@ let optimize
     ("wasm-opt"
      :: (common_options ()
         @ (if Config.Flag.trap_on_exception () then [] else [ "--traps-never-happen" ])
+        @ (if Config.Flag.use_new_eh () then [ "--translate-to-new-eh" ] else [])
         @ Option.value ~default:optimization_options.(level - 1) options
         @ [ Filename.quote input_file; "-o"; Filename.quote output_file ])
     @ opt_flag "--input-source-map" opt_input_sourcemap

compiler/lib/config.ml

@@ -105,6 +105,8 @@ module Flag = struct
   let wasi = o ~name:"wasi" ~default:false
 
   let trap_on_exception = o ~name:"trap-on-exception" ~default:false
+
+  let use_new_eh = o ~name:"use-new-eh" ~default:false
 end
 
 module Param = struct

compiler/lib/config.mli

@@ -80,6 +80,8 @@ module Flag : sig
 
   val trap_on_exception : unit -> bool
 
+  val use_new_eh : unit -> bool
+
   val enable : string -> unit
 
   val disable : string -> unit