Some improvements to the Cargo compiler file.
Use rustc's errorformat and add option to specify permanent parameters.
Updates based on kballard's feedback.
Added check for absolute file path, removed hard tab, and added documentation for new option.
Rename deprecated EnumSet methods in unit tests.
As of 4.9.2, gcc started passing -fno-lto to collect2, or to ld if collect2 cannot be found.  The latter is the case for our bundles, because we don't include collect2.  Unfortunately, ld does not understand this option and errors out.
On the bright side, -fno-use-linker-plugin still works to suppress gcc's LTO, so we can drop -fno-lto.
Move gcc back to rustlib\<triple>\bin
Prefer bundled linker.
Make Int inherit from Ord.

Previously Int inherited from PartialOrd (via Primitive)
but not Ord.  But integers have a total order, so
inheriting from Ord is appropriate. Fixes #18776.
Include some of the more popular Windows import libs into the bundle.
Fix upvars sometimes not being marked as used mutably

Drill down the loan path for McDeclared references as well since
it might lead to an upvar.  Closes #18769
Update test to cover #18769
First stage of struct variant field visibility changes

We need a snapshot before the parser can be adjusted.
Fix ICEs that involved quasi-quotation

* fixed get_tt for doc comments
* properly handle MatchNt in `quote`

Fixes #18763
Fixes #18775
Add Encodable and Decodable for VecMap
Use FnvHashMap instead of HashMap in rustc
Fix broken documentation link
Rogue 'panic' -> 'fail' in guide.

Should refer to handling panicking tasks like any other computation
that may _fail_, not any other computation that may _panic_.
auto merge of #18792 : sfackler/rust/struct-variants, r=alexcrichton

We need a snapshot before the parser can be adjusted.
Document ast::Ty_