message: bitcast allocated buffers before calling nested block function
diff: @@ -440,6 +440,8 @@ void Compiler::Visit(const stripe::Block& block) {
  auto malloc_func = MallocFunction();
  buffer = builder_.CreateCall(malloc_func, malloc_args, "");
  allocs.push_back(buffer);
  + llvm::Type* buftype = CType(ref.shape.type)->getPointerTo();
  + buffer = builder_.CreateBitCast(buffer, buftype);
  } else {
  // Pass in the current element address from the source buffer.
  // If a "from" name is specified, use that buffer; if not, that means
  