[Bug tree-optimization/77550] [6/7 Regression] std::deque with -O3 has infinite std::distance

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77550

--- Comment #14 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
The reduced testcase needs libstdc++.so from trunk. Otherwise you'll get
undefined reference errors to
_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE12_Alloc_hiderC1EPcOS3_ .