std: Use correct clone() stub
std: Use correct clone() stub

The previous clone() definition was written for 32bit PPC targets,
trying to execute it on a PPC64 machine lead to countless crashes.

Use the clone() definition kindly lifted from Musl libc.

andrewrk/zig,zig-lang/zig,raulgrell/zig,andrewrk/zig,raulgrell/zig,raulgrell/zig,zig-lang/zig,raulgrell/zig,raulgrell/zig,zig-lang/zig