[flang] [NFC] Repair build with GCC 7.3
authorpeter klausler <pklausler@nvidia.com>
Tue, 22 Jun 2021 18:29:14 +0000 (11:29 -0700)
committerpeter klausler <pklausler@nvidia.com>
Tue, 22 Jun 2021 20:52:30 +0000 (13:52 -0700)
commite3b2f1b6823f4f06da222545857809e6ee7962b6
tree61703483ab7b90de0160e08c9c43fff20fdcbb24
parent44feacc736e1ae35beafdf1cbfe59f7ff6688157
[flang] [NFC] Repair build with GCC 7.3

Work around two problems with GCC 7.3.
One is its inability to implement "constexpr operator=(...) = default;"
in a class with a std::optional<> component; another is a legitimate-
looking warning about an unused variable.

Differential Revision: https://reviews.llvm.org/D104731
flang/include/flang/Evaluate/type.h
flang/lib/Evaluate/formatting.cpp
flang/lib/Evaluate/type.cpp
flang/lib/Semantics/check-declarations.cpp