Bump support up to FreeBSD 13 and NetBSD 9.2

These releases are really exciting since they contained the patches we
worked to get upstreamed. It means that their /bin/sh interpreters all
work fine with Actually Portable Executable now.

libc/calls/execve-sysv.c

@@ -22,6 +22,7 @@
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
+#include "libc/intrin/kprintf.h"
 #include "libc/mem/alloca.h"
 #include "libc/paths.h"
 #include "libc/runtime/runtime.h"
@@ -81,11 +82,7 @@ int sys_execve(const char *prog, char *const argv[], char *const envp[]) {
     shargs[2] = prog;
     memcpy(shargs + 3, argv, (i + 1) * sizeof(char *));
   } else if (CanExecute(prog)) {
-    if (IsFreebsd() || IsNetbsd()) {
-      shargs[0] = firstnonnull(commandv("bash", buf, PATH_MAX), _PATH_BSHELL);
-    } else {
-      shargs[0] = _PATH_BSHELL;
-    }
+    shargs[0] = _PATH_BSHELL;
     shargs[1] = prog;
     memcpy(shargs + 2, argv + 1, i * sizeof(char *));
   } else {

libc/calls/unlinkat-nt.c

@@ -96,6 +96,7 @@ static textwindows bool IsDirectorySymlink(const char16_t *path) {
 
 static textwindows int sys_rmdir_nt(const char16_t *path) {
   int e, ms;
+  e = errno;
   for (ms = 1;; ms *= 2) {
     if (RemoveDirectory(path)) {
       return 0;
@@ -108,6 +109,7 @@ static textwindows int sys_rmdir_nt(const char16_t *path) {
      * Never could have imagined it'd be this bad.
      */
     if (GetLastError() == kNtErrorDirNotEmpty && ms <= 2048) {
+      errno = e;
       Sleep(ms);
       continue;
     } else {

libc/nexgen32e/rldecode.S

@@ -19,7 +19,7 @@
 #include "libc/macros.internal.h"
 .text.startup
 
-//	Seventeen byte decompressor.
+//	Thirteen byte decompressor.
 //
 //	@param	di points to output buffer
 //	@param	si points to uint8_t {len₁,byte₁}, ..., {0,0}
@@ -32,8 +32,7 @@ rldecode:
 	xchg	%al,%cl
 	lodsb
 	jrcxz	2f
-1:	stosb
-	.loop	1b
+	rep stosb
 	jmp	0b
 2:	.leafepilogue
 	.endfn	rldecode,globl