Reference declarator in for-range-declaration of 'for...' loop causes crash

[Jenny-fa]

In the following C++ source code, when the loop variable i is either an lvalue or rvalue reference, Clang will crash due to a failed assertion in VarDecl::checkInitIsICE().

// tuple-for.cpp

#include <iostream>
#include <tuple>

int main() {
  auto t = std::make_tuple(0, 0.1, "meep");

  for... (auto i : t) // This is fine.
    std::cout << i << '\n';

  for... (auto &i : t) // Crash!
    std::cout << i << '\n';

  for... (auto &&i : t) // Crash!
    std::cout << i << '\n';

  return 0;
}