move parts of rustrt/core to std

[brson]

Some things that probably should be in std are in core and rt, primarily because rt is the only place we put native code.

Right now uv is linked to rt, but the bindings are (rightly imo) in std. There is also some native glue code used by the uv bindings. Deflate is in core, for use by the compiler, and I think this is probably because the native deflate code is in rt.

Core and rt are merging and will be statically linked in the future and things are not organized quite right.

I suggest the following:

• Move core::flate to std, linking to rustrt
• Rename rustrt to rustcore_native
• Add ruststd_native, statically linked to std
• Move uv and deflate native code to ruststd_native
• Statically link rustrt to core Statically link the runtime to core #3361

[brson]

Not 0.6

[bblum]

revisiting for triage; don't have anything to add

[huonw]

Triage: flate is now in extra, and the amount of code in rustrt is dropping dramatically as almost everything moves into std::rt.

I'd say this issue can be closed as out-of-date as it will happen naturally.

[brson]

Closing. There's still more reorganization I'd like to do here, but this is pretty out of date.