Add mes and mescc-tools-extra

mescc-tools-extra contains two important tools:
- cp
- chmod

mes first builds itself from a mes 0.21 seed as used by guix, and then
builds a mes 0.22 and then mes 0.22 using that created mes 0.22.

It does /not/ use bootstrap.sh as we don't have a proper shell at this
point, it has been manually adapted for kaem.

sysa/mes-0.22/lib/mach/mach_thread_self.S

@@ -0,0 +1,19 @@
+#if 1	
+#include <mach/machine/syscall_sw.h>
+kernel_trap (__mach_thread_self,-27,0)
+// weak_alias (__mach_thread_self, mach_thread_self)
+#else
+        .globl __mach_thread_self
+        .type __mach_thread_self,@function
+        .align 1<<4
+__mach_thread_self: .cfi_startproc
+        movl $ -27,%eax
+        .byte 0x9a
+        .long 0
+        .word 0x7
+        ret
+        .cfi_endproc
+        .size __mach_thread_self,.-__mach_thread_self
+        .weak mach_thread_self 
+        mach_thread_self = __mach_thread_self
+#endif