Make terminal ui binaries work well everywhere

Here's some screenshots of an emulator tui program that was compiled on
Linux, then scp'd it to Windows, Mac, and FreeBSD.

https://justine.storage.googleapis.com/blinkenlights-cmdexe.png
https://justine.storage.googleapis.com/blinkenlights-imac.png
https://justine.storage.googleapis.com/blinkenlights-freebsd.png
https://justine.storage.googleapis.com/blinkenlights-lisp.png

How is this even possible that we have a nontrivial ui binary that just
works on Mac, Windows, Linux, and BSD? Surely a first ever achievement.

Fixed many bugs. Bootstrapped John McCarthy's metacircular evaluator on
bare metal in half the size of Altair BASIC (about 2.5kb) and ran it in
emulator for fun and profit.

libc/str/tpenc.S

@@ -24,19 +24,15 @@
 /
 /	@param	edi is int to encode
 /	@return	rax is word-encoded byte buffer
-/	@clob	edi,rax,flags
 /	@note	invented on a napkin in a new jersey diner
 tpenc:	.leafprologue
 	.profilable
-	push	%rcx
-	push	%rdx
 	mov	%edi,%edi
 	xor	%eax,%eax
 	cmp	$127,%edi
 	jbe	3f
 	bsr	%edi,%ecx
-	ezlea	kTpenc,dx
-	mov	-7*(1+1)(%rdx,%rcx,2),%ecx
+	mov	kTpenc-7*(1+1)(,%rcx,2),%ecx
 1:	mov	%edi,%edx
 	shr	$6,%edi
 	and	$0b00111111,%dl
@@ -47,12 +43,11 @@ tpenc:	.leafprologue
 	jnz	1b
 2:	or	%ch,%al
 3:	or	%rdi,%rax
-	pop	%rdx
-	pop	%rcx
 	.leafepilogue
 	.endfn	tpenc,globl
 
 	.rodata
+	.align	4
 kTpenc:	.rept	4			# MSB≤10 (0x7FF)
 	.byte	1,0b11000000		# len,mark
 	.endr
@@ -68,4 +63,5 @@ kTpenc:	.rept	4			# MSB≤10 (0x7FF)
 	.rept	6			# MSB≤31 (0xffffffff)
 	.byte	5,0b11111100		# len,mark
 	.endr
+	.zero	2
 	.endobj	kTpenc