Make redbean StoreAsset() work better

- Better UBSAN error messages
- POSIX Advisory Locks polyfills
- Move redbean manual to /.help.txt
- System call memory safety in ASAN mode
- Character classification now does UNICODE

test/libc/intrin/test.mk

@@ -26,6 +26,7 @@ TEST_LIBC_INTRIN_DIRECTDEPS =				\
 	LIBC_FMT					\
 	LIBC_INTRIN					\
 	LIBC_LOG					\
+	LIBC_MEM					\
 	LIBC_NEXGEN32E					\
 	LIBC_RAND					\
 	LIBC_RUNTIME					\