Consolidate raw representations of rust values

This moves the raw struct layout of closures, vectors, boxes, and strings into a
new `unstable::raw` module. This is meant to be a centralized location to find
information for the layout of these values.

As safe method, `repr`, is provided to convert a rust value to its raw
representation. Unsafe methods to convert back are not provided because they are
rarely used and too numerous to write an implementation for each (not much of a
common pattern).
auto merge of #7820 : pnkfelix/rust/fill-in-some-missing-rustc-lib-dependences, r=graydon

r? anyone

Fix #8057

This commit fixes some oversights in the Makefile where rustc could be
invoked without some of its dependencies yet in place.  (I encountered
the problem in practice; its not just theoretical.)

As written in Makefile.in, $(STAGE$(1)_T_$(2)_H_$(3)) is the way one
writes an invocation of rustc where $(1) is the stage number $(2) is
the target triple $(3) is the host triple.  (Other uses of the macro
may plug in actual values or different parameters in for those three
formal parameters.)

When you have invocations of $(STAGE...), you need to make sure that
its dependences are satisfied; otherwise, if someone is using `make
-jN` for certain (large-ish) `N`, one can encounter situations where
GNU make attempts to invoke `rustc` before it has actually copied some
of its libraries into place, such as libmorestack.a, which causes a
link failure when the rustc invocation attempts to link in those
libraries.

In this case, the main prerequisite to add is TSREQ$(1)_T_$(2)_H_$(3),
which is described in Makefile.in as "Prerequisites for using the
stageN compiler to build target artifacts"

----

In addition to adding the extra dependences on TSREQ..., I also
replaced occurrences of the pattern:

    TSREQ$(1)_T_$(2)_H_$(3)
    $$(TLIB$(1)_T_$(2)_H_$(3))/$(CFG_STDLIB_$(2))
    $$(TLIB$(1)_T_$(2)_H_$(3))/$(CFG_EXTRALIB_$(2))

with:

    SREQ$(1)_T_$(2)_H_$(3)

which is equivalent to the above, as defined in Makefile.in

----

Finally, for the cases where TSREQ was missing in tests.mk, I went
ahead and put in a dependence on SREQ rather than just TSREQ, since it
was not clear to me how one could expect to compile those cases
without stdlib and extralib.

(It could well be that I should have gone ahead and done the same in
 other cases where I saw TSREQ was missing, and put SREQ in those
 cases as well.  But this seemed like a good measure for now, without
 needing to tax my understanding of the overall makefile
 infrastructure much further.)
rustpkg: Don't assume a non-numeric refspec is a tag

Just pass it directly to git, without prefixing it with tags/
Improve the camel case warning a bit.
Eliminate unused variable warnings.
auto merge of #7979 : crnobog/rust/auxfiles-path-windows, r=cmr
Deny all warnings by default in doc tests

Allow some common ones that are good for examples, however.
auto merge of #7986 : alexcrichton/rust/raw-repr, r=brson

This moves the raw struct layout of closures, vectors, boxes, and strings into a
new `unstable::raw` module. This is meant to be a centralized location to find
information for the layout of these values.

As safe method, `unwrap`, is provided to convert a rust value to its raw
representation. Unsafe methods to convert back are not provided because they are
rarely used and too numerous to write an implementation for each (not much of a
common pattern).

This is progress on #6790. I tried to get a nice interface for a trait to implement in the raw module, but I was unable to come up with one. The hard part is that there are so many different directions to go from one way to another that it's difficult to find a pattern to follow to implement a trait with. Someone else might have some better luck though.
docs: Talk about tags that aren't versions in the "Package identifiers" section
librustc: Respect no_mangle attribute on statics.
Register snapshots.
auto merge of #8050 : msullivan/rust/cleanup, r=graydon

And a couple other things. Fix up some unused variable warnings, and improve the camel case lint message a little.
librustc: Unify name mangling for functions and statics.
auto merge of #8001 : crnobog/rust/xfail-win32-7999, r=cmr
Remove unnecessary #[path = "***/mod.rs"] lines.

Fixes #7922.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
rustc: reorganize driver, replace compile_upto with multiple more-obvious functions.
librustc: Stop trying to make invalid slice with vec in static.
Add test for #5917.
auto merge of #8040 : luqmana/rust/rtn, r=brson

Implements various missing tcp & udp methods.. Also fixes handling ipv4-mapped/compatible ipv6 addresses and addresses the XXX on `status_to_maybe_uv_error`.

r? @brson
auto merge of #8045 : michaelwoerister/rust/destructuring, r=jdm

As the title says, valid debug info is now generated for any kind of pattern-based bindings like an example from the automated tests: 
```rust
let ((u, v), ((w, (x, Struct { a: y, b: z})), Struct { a: ae, b: oe }), ue) =
    ((25, 26), ((27, (28, Struct { a: 29, b: 30})), Struct { a: 31, b: 32 }), 33);  
```
(Not that you would necessarily want to do a thing like that :P )

Fixes #2533