Internal error: assertion failed at: "shared/cfe/edgcpfe/decl_inits.c", line 588

I am running into the following ICE with the following relatively minimalized test case.

Internal error: assertion failed at: "shared/cfe/edgcpfe/decl_inits.c", line 588

template <char>
struct Index {
  constexpr Index() : value_(0) {
  }

 private:
  int value_;
};

template <int>
int foo() {
  static constexpr Index<'i'> i;
  return 0;
}

int bar() {
  return foo<3>();
}

See versions below
 

[...]:~/test> gcc --version
gcc (GCC) 6.3.0 20161221 (Cray Inc.)
Copyright (C) 2016 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[...]:~/test> icpc --version
icpc (ICC) 17.0.2 20170213
Copyright (C) 1985-2017 Intel Corporation.  All rights reserved.

[...]:~/test> gcc -std=c++14 -c -o test.o test.cpp
[...]:~/test> icpc -std=c++14 -c -o test.o test.cpp
Internal error: assertion failed at: "shared/cfe/edgcpfe/decl_inits.c", line 588


compilation aborted for test.cpp (code 4)

This can be reproduced across lots of platforms and compiler versions, though this particular instance is in the Cray Linux Environment with PrgEnv-intel/6.0.3 and gcc/6.3.0