pytorch

4d2502a0 - fix explicitly defaulted constexpr assignment operator fails to compile error for gcc 5.3.0 (#36561)

fix explicitly defaulted constexpr assignment operator fails to compile error for gcc 5.3.0 (#36561) Summary: gcc 5.3.0 has an issue which can't define default function as constexpr, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68754. for works for gcc 5.3.0, not define default function as constexpr function now. Pull Request resolved: https://github.com/pytorch/pytorch/pull/36561 Differential Revision: D21024109 Pulled By: ezyang fbshipit-source-id: 58fce704625b7d0926e40b6b12841ebbe392c59c