message: Add block-trace flag to CLI.
diff: @@ -179,6 +179,10 @@ struct Run {
  #[structopt(long = "call-trace")]
  call_trace: bool,
  + // Enable the BlockTrace middleware.
  + #[structopt(long = "block-trace")]
  + block_trace: bool,
  +
  /// The command name is a string that will override the first argument passed
  /// to the wasm program. This is used in wapm to provide nicer output in
  /// help commands and error messages of the running wasm program
  @@ -834,6 +838,10 @@ fn get_compiler_by_backend(backend: Backend, opts: &Run) -> Option<Box<dyn Compi
  use wasmer_middleware_common::call_trace::CallTrace;
  middlewares.push(CallTrace::new());
  }
  + if opts.block_trace {
  + use wasmer_middleware_common::block_trace::BlockTrace;
  + middlewares.push(BlockTrace::new());
  + }
  middlewares
  };
  