* synchronize zig1.c from zig-wasi external project
 * change the way argv works to avoid absolute paths
 * autodetect isatty
 * compiler_rt: disable some functions when object format is C
 * add missing flag from config.zig.in

The next problem is that compiling compiler_rt.c with gcc gives
"conflicting types" errors for `__eqhf2` and friends.