Comment 2 for bug 1618799

(gdb) bt
#0 0x0000000000643a8e in ?? ()
#1 0x0000000000643898 in ?? ()
#2 0x00000000006427f2 in ?? ()
#3 0x0000000000d4e6fe in gfc_generate_function_code(gfc_namespace*) ()
#4 0x0000000000d2c6b6 in gfc_parse_file() ()
#5 0x00000000011e6166 in ?? ()
#6 0x0000000001236373 in ?? ()
#7 0x0000000000d0ca69 in toplev::main(int, char**) ()
#8 0x0000000000d0cdba in main ()

this is fixed in gcc-5 in zesty and in gcc-6.