bad_alloc with unordered_map initialization_list and MMX instruction, possible heap corruption?

I am getting a bad_alloc thrown from the code below compiled with gcc (tried 4.9.3, 5.40 and 6.2). gdb tells me it happens on the last line with the initalizer_list for the unordered_map. If I comment out the mmx instruction _m_maskmovq there is no error. Similarly if I comment out the initialization of the unordered_map this is no error. Only when invoking the mmx instruction and initializing the unordered_map with an initializer_list do I get the bad_alloc. If I default construct the unordered_map and call map.emplace(1,1) there is also no error. I've run this on a centos7 machine with 48 cores and 376 GB RAM and also on a Dell laptop under Ubunutu WSL with the same result. What is going on here? Is the MMX instruction corrupting the heap? Valgrind didn't seem to identify anything useful.

Compiler command and output:

$g++ -g -std=c++11 main.cpp
$./a.out
   terminate called after throwing an instance of 'std::bad_alloc'
   what():  std::bad_alloc
   Aborted

Source code (main.cpp):

#include <immintrin.h>
#include <unordered_map>

int main()
{
  __m64 a_64 = _mm_set_pi8(0,0,0,0,0,0,0,0);
  __m64 b_64 = _mm_set_pi8(0,0,0,0,0,0,0,0);
  char dest[8] = {0};
  _m_maskmovq(a_64, b_64, dest);

  std::unordered_map<int, int> map1;
}