alloca cannot be a function. #define it to the gcc builtin if possible
[musl] / crt /
drwxr-xr-x   ..
drwxr-xr-x - arm
-rw-r--r-- 0 crt1.c
-rw-r--r-- 0 crti.c
-rw-r--r-- 0 crtn.c
drwxr-xr-x - i386
drwxr-xr-x - x86_64