[Toybox] new gcc screwing up single-toy builds

[Isaac Dunham]

Hello,
On Alpine Linux edge (latest musl release, gcc 4.8.2), scripts/single.sh 
consistently gives this warning:

scripts/make.sh
Make generated/config.h from .singleconfig.
Extract configuration information from toys/*.c files...
Generate headers from toys/*/*.c...
generated/newtoys.h generated/flags.h generated/globals.h generated/help.h
Library probe...
Compile toybox...
main.c: In function 'main':
main.c:182:13: warning: array subscript is above array bounds [-Warray-bounds]
     toy_list->toy_main();
             ^

This happens with any command, and results in a command that segfaults before
entering <command>_main().

Regular builds with at least two commands enabled do not display this issue.
I have not tested enabling one command and TOYBOX_CONTAINER.

Thank you,
Isaac Dunham