cc,wasi: package emulations as static archives

This replicates the expected behavior when using `clang` with
upstream `wasi-libc` sysroot: linking emulated subcomponents
such as process clocks or signals requires an explicit link flag
in the compiler invocation, for example:

```
zig cc -target wasm32-wasi -lwasi-emulated-process-clocks main.c -o main.wasm
```
93a4403271Jakub Konka committed on 6/8/2021, 11:25:38 PMparent6f6182a
2 files changedLine totals unavailable