Method make_concat_array

include/floor/constexpr/const_string.hpp:213–224

	//! creates a storage array from two c strings
	//! (note that len_0 should have been subtracted by 1 beforehand, so that the \0 of the first string isn't copied)
	template <size_t n> static constexpr storage_array<n> make_concat_array(const size_t len_0, const size_t len_1,
																			const char* str_0, const char* str_1) {
		storage_array<n> ret {};
		size_t i = 0;
		for(; i < len_0; ++i) {
			ret.data[i] = str_0[i];
		}
		for(size_t j = 0; j < len_1; ++j, ++i) {
			ret.data[i] = str_1[j];
		}
		return ret;
	}
	
	//! hash computation helper function
	static constexpr uint32_t rotl32(uint32_t x, int r) {