message: Remove black box inline asm fallback
  It isn't used anymore since the introduction of the black_box intrinsic
diff: @@ -18,10 +18,7 @@ pub(crate) fn codegen_inline_asm<'tcx>(
  ) {
  // FIXME add .eh_frame unwind info directives
  - if template.is_empty() {
  - // Black box
  - return;
  - } else if template[0] == InlineAsmTemplatePiece::String("int $$0x29".to_string()) {
  + if template[0] == InlineAsmTemplatePiece::String("int $$0x29".to_string()) {
  let true_ = fx.bcx.ins().iconst(types::I32, 1);
  fx.bcx.ins().trapnz(true_, TrapCode::User(1));
  return;
  