Adds a new ABI for the EFIAPI calls. This ABI should reflect the latest
version of the UEFI specification at the time of commit (UEFI spec 2.8,
URL below). The specification says that for x86_64, we should follow the
win64 ABI, while on all other supported platforms (ia32, itanium, arm,
arm64 and risc-v), we should follow the C ABI.

To simplify the implementation, we will simply follow the C ABI on all
platforms except x86_64, even those technically unsupported by the UEFI
specification.

https://uefi.org/sites/default/files/resources/UEFI_Spec_2_8_final.pdf

Use revisions to run the EFIABI in multiple configurations, compiling
for each supported UEFI platform, and checking the ABI generated in the
LLVM IR is correct.

Use no_core to make it easier to test.

… pretty-printing mechanism.

…nikomatsakis

Custom lifetime error for `impl` item doesn't conform to `trait`

Partly addresses rust-lang#42706, rust-lang#41343, fix rust-lang#40900.

…thewjasper

Lint ignored `#[inline]` on function prototypes

Fixes rust-lang#51280.

- Adds a `unused_attribute` lint for `#[inline]` on function prototypes.
- As a consequence, foreign items, impl items and trait items now have their attributes checked, which could cause some code to no longer compile (it was previously erroneously ignored).

Call out the types that are non local on E0117

CC rust-lang#24745.

Update backtrace to 0.3.40

Diff: rust-lang/backtrace-rs@0.3.37...b5cc5b1

Pretty low risk, considering the only changes are in low-tier targets.

r? @cramertj
cc @alexcrichton

Improve the "try using a variant of the expected type" hint.

Fix rust-lang#65494.

- Change type-printing output.
- Use `span_to_snippet` when possible.
- Change the message to `try using a variant of the expected enum`

Add new EFIAPI ABI

Fixes rust-lang#54527

Adds a new ABI, "efiapi", which reflects the calling convention as specified by [the current spec UEFI spec](https://uefi.org/sites/default/files/resources/UEFI%20Spec%202_7_A%20Sept%206.pdf#G6.999903). When compiling for x86_64, we should select the `win64` ABI, while on all other architectures (Itanium, x86, ARM and ARM64 and RISC-V), we should select the `C` ABI.

Currently, this is done by just turning it into the C ABI everywhere except on x86_64, where it's turned into the win64 ABI. Should we prevent this ABI from being used on unsupported architectures, and if so, how would this be done?

…r=alexcrichton

Enable dist for MIPS64 musl targets

Continuing work in rust-lang#63165, necessary libc changes are in place and published so here we go!

…mertj

Better pretty printing for const raw pointers

closes rust-lang#65349, hopefully.