Update ETL_CONSTEXPR and C++14 desgination from type_def #265

Job	Run time
GCC C++03 Linux No STL (ubuntu-22.04)	31s
GCC C++11 Linux No STL (ubuntu-22.04)	51s
GCC C++03 Linux STL (ubuntu-22.04)	31s
GCC C++11 Linux No STL Force C++03 (ubuntu-22.04)	49s
GCC C++11 Linux STL (ubuntu-22.04)	56s
GCC C++11 Linux STL Force C++03 (ubuntu-22.04)	55s
GCC C++14 Linux STL (ubuntu-22.04)	57s
GCC C++14 Linux No STL (ubuntu-22.04)	51s
GCC C++14 Linux No STL Force C++03 (ubuntu-22.04)	53s
GCC C++14 Linux STL Force C++03 (ubuntu-22.04)	58s
GCC C++17 Linux No STL (ubuntu-22.04)	1m 4s
GCC C++17 Linux No STL Force C++03 (ubuntu-22.04)	1m 3s
GCC C++17 Linux STL (ubuntu-22.04)	1m 17s
GCC C++17 Linux STL Force C++03 (ubuntu-22.04)	1m 24s
GCC C++20 Linux No STL (ubuntu-22.04)	1m 25s
GCC C++20 Linux No STL Force C++03 (ubuntu-22.04)	1m 26s
GCC C++20 Linux STL (ubuntu-22.04)	1m 55s
GCC C++20 Linux STL Force C++03 (ubuntu-22.04)	1m 57s
	19m 43s

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