Added proper cross-compiler reqs

Some libc slash libk todos

@@ -1,3 +1,15 @@
+To be able to do a hosted GCC cross-compiler/system-specific cross-compiler
+===========================================================================
+/* NB: functions don't *need* to be implemented, just prototyped */
+sys/types.h: pid_t
+errno.h: must exist
+stdlib.h: abort(), atexit(), atoi(), free(), getenv(), malloc()
+stdio.h: FILE, stderr, size_t, SEEK_SET, fflush(), fclose(), fopen(), fread(),
+         fseek(), ftell(), fwrite(), setbuf(), fprintf(), vfprintf()
+string.h: size_t, memcpy(), memset(), strcpy(), strlen()
+time.h: must exist
+unistd.h: pid_t, fork(), execv(), execve(), execvp()
+
 /* NB: This list is ordered. i.e. cat needs stuff from asa to work! */
 
 For sh