remove libc dependency of zig0 building libstage2

Rather than `zig0 build ...` the build now does
`zig0 build-lib ...`, avoiding the requirement of linking the build
script, and thus avoiding the requirement of finding native libc,
for systems where libc is the system ABI.
7eb0a3edceAndrew Kelley committed on 2/16/2020, 11:57:34 PMparent39ee46a
6 files changedLine totals unavailable