Get binaries closer to running without an o/s

blinkenlights now does a pretty good job emulating what happens when
binaries boot from BIOS into long mode. So it's been much easier to
debug the bare metal process and wrinkle out many issues.

libc/sysv/systemfive.S

@@ -166,6 +166,8 @@ systemfive.xnu:
 	.init.start 300,_init_systemfive
 	push	%rbx
 	push	%rsi
+	testb	$METAL,(%rdi)			# @see ape/ape.S
+	jnz	systemfive.init.metal
 	testb	$XNU,(%rdi)			# @see libc/crt/crt.S
 	jnz	systemfive.init.xnu
 	testb	$FREEBSD,(%rdi)			# @see libc/crt/crt.S
@@ -181,6 +183,11 @@ systemfive.init.linux:
 	push	$LINUX
 	ezlea	syscon.linux,si
 	jmp	systemfive.init.os
+systemfive.init.metal:
+	pushb	systemfive.linux-.Lanchorpoint
+	push	$METAL
+	ezlea	syscon.linux,si
+	jmp	systemfive.init.os
 systemfive.init.windows:
 	pushb	systemfive.enosys-.Lanchorpoint
 	push	$WINDOWS