Generate return-old-value overload of `operator++`/`operator--` only … #4

Job	Run time
ubu-24 \| g++-14 \| c++2b \| libstdc++ \| ubuntu-24.04	19m 19s
ubu-24 \| g++-13 \| c++2b \| libstdc++ \| ubuntu-24.04	10m 17s
ubu-20 \| g++-10 \| c++20 \| libstdc++ \| ubuntu-20.04	8m 46s
ubu-24 \| clang++-18 \| c++20 \| libstdc++ \| ubuntu-24.04	9m 9s
ubu-24 \| clang++-18 \| c++23 \| libc++-18-dev \| ubuntu-24.04	9m 33s
ubu-22 \| clang++-15 \| c++20 \| libstdc++ \| ubuntu-22.04	7m 49s
ubu-22 \| clang++-15 \| c++20 \| libc++-15-dev \| ubuntu-22.04	7m 42s
ubu-20 \| clang++-12 \| c++20 \| libstdc++ \| ubuntu-20.04	7m 22s
mac-14 \| clang++ \| c++2b \| default \| macos-14	4m 12s
mac-13 \| clang++ \| c++2b \| default \| macos-13	7m 13s
mac-13 \| clang++-15 \| c++2b \| default \| macos-13	10m 40s
win-22 \| cl.exe \| c++latest \| default \| windows-2022	5m 33s
win-22 \| cl.exe \| c++20 \| default \| windows-2022	5m 19s
aggregate-results	10s
	1h 53m 4s

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