Use constructors for functable again #47

Job	Run time
Ubuntu GCC	13s
Ubuntu 20.04 GCC	16s
Ubuntu GCC OSB	13s
Ubuntu GCC Compat No Opt	8s
Ubuntu GCC ARM SF	22s
Ubuntu GCC ARM SF Compat No Opt	21s
Ubuntu GCC ARM HF	23s
Ubuntu GCC ARM HF No ACLE	1m 11s
Ubuntu GCC ARM HF No NEON	23s
Ubuntu GCC ARM HF Compat No Opt	28s
Ubuntu GCC AARCH64	29s
Ubuntu GCC AARCH64 No ACLE	32s
Ubuntu GCC AARCH64 No NEON	41s
Ubuntu GCC AARCH64 Compat No Opt	22s
Ubuntu GCC MIPS	23s
Ubuntu GCC MIPS64	34s
Ubuntu GCC PPC	21s
Ubuntu GCC PPC No Power8	28s
Ubuntu GCC PPC64	27s
Ubuntu GCC PPC64LE	1m 12s
Ubuntu GCC S390X	19s
Ubuntu GCC S390X No vectorized CRC32	29s
Ubuntu GCC S390X DFLTCC	22s
Ubuntu GCC S390X DFLTCC Compat	27s
Ubuntu Emscripten WASM32	40s
macOS GCC Symbol Prefix	49s
macOS GCC Symbol Prefix (ARM64)	27s
macOS GCC Symbol Prefix & Compat	44s
macOS GCC Symbol Prefix & Compat (ARM64)	27s
macOS GCC	46s
macOS GCC (ARM64)	21s
	15m 18s

Provide feedback