fix missing_doc lint on private traits

Fixes #10069.
Reduce the aggressiveness of reachability

Previously, all functions called by a reachable function were considered
reachable, but this is only the case if the original function was possibly
inlineable (if it's type generic or #[inline]-flagged).
Drop struct fields if the user destructor fails

This commit changes drop glue generated for structs to use the invoke LLVM
instruction instead of call. What this means is that if the user destructor
triggers an unwinding, then the fields of the struct will still ge dropped.

This is not an attempt to support failing while failing, as that's mostly a
problem of runtime support. This is more of an issue of soundness in making sure
that destructors are appropriately run. The test included fails before this
commit, and only has one call to fail!(), yet it doesn't destroy its struct
fields.
Fix typo in to_digit
Bump required pandoc version to 1.9.

Earlier versions of pandoc don't have the default.html5 and thus,
building the docs fail.

Signed-off-by: Noufal Ibrahim <noufal@nibrahim.net.in>
Use consistent capitalization in makefile errors

In Rust we don't like capital letters.
Register new snapshots

Closes #2240
Fix installation with DESTDIR
auto merge of #10222 : nibrahim/rust/docfix, r=brson

Earlier versions of pandoc don't have the `default.html5` template file. When `make docs` is run, the build process fails with this message.

    pandoc: doc/rust.html
    pandoc: /usr/share/pandoc-1.8.2.1/templates/default.html5: openFile: does not exist (No such file or directory)
    
    node.js:201
            throw e; // process.nextTick error, or 'error' event on first tick
                  ^
    Error: write EPIPE
        at errnoException (net.js:670:11)
        at Object.afterWrite [as oncomplete] (net.js:503:19)
    make: *** [doc/rust.html] Error 1
Stop propagating link arguments across crates

This is a fairly brittle modle that doesn't scale well across many crates. It's
unlikely that all of the downstream crates will have all of the original native
dependencies of all the upstream crates. In the case that FFI functions are
reachable, then it should be the responsibility of the downstream crate to link
against the correct library, or the upstream crate should prevent the functions
from being reachable.
Statically link sundown to librustdoc

Closes #10103
auto merge of #10232 : brson/rust/destdir, r=thestinger
Rustdoc: Properly strip private modules

A private module will survive the strip-private pass if it contains
trait implementations, which aren't stripped until a separate pass in
render.
auto merge of #10225 : Jurily/rust/master, r=alexcrichton
auto merge of #10229 : brson/rust/warnings, r=thestinger

In Rust we don't like capital letters.
auto merge of #10230 : alexcrichton/rust/snapshots, r=brson

Closes #2240
auto merge of #10233 : sfackler/rust/private-module, r=alexcrichton

A private module will survive the strip-private pass if it contains
trait implementations, which aren't stripped until a separate pass in
render.
auto merge of #10217 : alexcrichton/rust/less-reachable, r=pcwalton

Previously, all functions called by a reachable function were considered
reachable, but this is only the case if the original function was possibly
inlineable (if it's type generic or #[inline]-flagged).
auto merge of #10165 : dcrewi/rust/missing-doc-on-private-trait, r=cmr

Fixes #10069.
Updated debugging metadata for ty_nil and ty_bot

ty_nil will now report as "()" in gdb
ty_bot will now report as "!" in gdb

Added test to confirm basic types debugging metadata.

This fixes #9226