const internal/abi.EffectiveFloatRegSize

2 uses

	internal/abi (current package)
		abi_amd64.go#L17: 	EffectiveFloatRegSize = 8

	reflect
		abi.go#L35: 	floatRegSize = uintptr(abi.EffectiveFloatRegSize * goexperiment.RegabiArgsInt)