[clang] SequenceChecker: C++17 sequencing rule for overloaded operators.

In C++17 the operand(s) of an overloaded operator are sequenced as for
the corresponding built-in operator when the overloaded operator is
called with the operator notation ([over.match.oper]p2).

Reported in PR35340.

Differential Revision: https://reviews.llvm.org/D81330

Reviewed By: rsmith