message: FunctionCx: Fix FunctionCx initialization in trans_fn()
diff: @@ -16,14 +16,9 @@ pub(crate) fn trans_fn<'tcx, B: Backend + 'static>(
  let (name, sig) = get_function_name_and_sig(tcx, cx.module.isa().triple(), instance, false);
  let func_id = cx.module.declare_function(&name, linkage, &sig).unwrap();
  - // Make FunctionBuilder
  - let context = &mut cx.cached_context;
  - context.clear();
  - context.func.name = ExternalName::user(0, func_id.as_u32());
  - context.func.signature = sig;
  - context.func.collect_debug_info();
  let mut func_ctx = FunctionBuilderContext::new();
  - let mut bcx = FunctionBuilder::new(&mut context.func, &mut func_ctx);
  + let mut func = Function::new();
  + let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
  // Predefine blocks
  let start_block = bcx.create_block();
  @@ -66,6 +61,13 @@ pub(crate) fn trans_fn<'tcx, B: Backend + 'static>(
  });
  }
  + // Make FunctionBuilder
  + let context = &mut fx.cx.cached_context;
  + context.clear();
  + context.func.name = ExternalName::user(0, func_id.as_u32());
  + context.func.signature = sig;
  + context.func.collect_debug_info();
  +
  // Recover all necessary data from fx, before accessing func will prevent future access to it.
  let instance = fx.instance;
  let mut clif_comments = fx.clif_comments;
  @@ -74,7 +76,7 @@ pub(crate) fn trans_fn<'tcx, B: Backend + 'static>(
  let cold_blocks = fx.cold_blocks;
  crate::pretty_clif::write_clif_file(
  - cx.tcx,
  + fx.cx.tcx,
  "unopt",
  None,
  instance,
  @@ -94,10 +96,10 @@ pub(crate) fn trans_fn<'tcx, B: Backend + 'static>(
  // instruction, which doesn't have an encoding.
  context.compute_cfg();
  context.compute_domtree();
  - context.eliminate_unreachable_code(cx.module.isa()).unwrap();
  + context.eliminate_unreachable_code(fx.cx.module.isa()).unwrap();
  // Define function
  - let module = &mut cx.module;
  + let module = &mut fx.cx.module;
  tcx.sess.time(
  "define function",
  || module.define_function(
  @@ -109,18 +111,18 @@ pub(crate) fn trans_fn<'tcx, B: Backend + 'static>(
  // Write optimized function to file for debugging
  crate::pretty_clif::write_clif_file(
  - cx.tcx,
  + fx.cx.tcx,
  "opt",
  - Some(cx.module.isa()),
  + Some(fx.cx.module.isa()),
  instance,
  &context,
  &clif_comments,
  );
  // Define debuginfo for function
  - let isa = cx.module.isa();
  - let debug_context = &mut cx.debug_context;
  - let unwind_context = &mut cx.unwind_context;
  + let isa = fx.cx.module.isa();
  + let debug_context = &mut fx.cx.debug_context;
  + let unwind_context = &mut fx.cx.unwind_context;
  tcx.sess.time("generate debug info", || {
  if let Some(debug_context) = debug_context {
  debug_context.define_function(instance, func_id, &name, isa, context, &source_info_set, local_map);
  