postgis3 @3.2.0_5+postgresql14+proj8+raster+topology: Dependency requires c++14 instead of 11 now.

[beporter (Brian Porter)]

• Cleaned and ran sudo port install postgis3 again: Failed again.
• Checked the ​problem hotlist: Not listed.
• ​Searched for existing tickets: #67339 is similar but looks to be a missing directory, not CXX_STANDARD related.
• Problem is specific to compilation.
• Problem is not related to port upgrade.

This seems to be the relevant bit from the log file:

:info:build In file included from flatgeobuf_c.cpp:26:
:info:build In file included from ./feature_generated.h:7:
:info:build In file included from include/flatbuffers/flatbuffers.h:20:
:info:build In file included from include/flatbuffers/base.h:241:
:info:build In file included from /opt/local/include/absl/strings/string_view.h:39:
:info:build In file included from /opt/local/include/absl/base/attributes.h:37:
:info:build In file included from /opt/local/include/absl/base/config.h:86:
:info:build /opt/local/include/absl/base/policy_checks.h:79:2: error: "C++ versions less than C++14 are not supported."
:info:build #error "C++ versions less than C++14 are not supported."

Assuming absl is actually ​abseil, then there's a ​recent release note indicating it now requires c++14.

This must be a second-level dependency though, because the ​Postgis3 Portfile doesn't contain any reference to c++11. Possibly ​protobuf-c, which is a dependency of postgis3 and has compiler.cxx_standard 2011 in its Portfile?