libcore: Get rid of useless mem::forget wrapper.
Change how libgetopts handles options grouped together

As soon as an option is found that takes an argument, consume the rest
of the string and store it into i_arg. Previously this would only happen
if the character after the option was not a recognized option.

Addresses issue #16348
Make note that Ordering is builtin.

This way people won't try to copy/paste it in.
librustc: Fix a couple of cases in which unboxed closure typechecking
code wasn't considering the zero-argument case.

Closes #16168.
librustc: Resolve nested vtable parameters in overloaded calls.

Closes #16508.
docs: don't claim struct layout is specified, but mention repr
librustc: handle repr on structs, require it for ffi, unify with packed

As of RFC 18, struct layout is undefined. Opting into a C-compatible struct
layout is now down with #[repr(C)]. For consistency, specifying a packed
layout is now also down with #[repr(packed)]. Both can be specified.

To fix errors caused by this, just add #[repr(C)] to the structs, and change
 #[packed] to #[repr(packed)]

Closes #14309

[breaking-change]
Add #[repr(C)] to all the things!
manual: fix link
Add detailed note about Substs to ty_enum
liblibc: don't use int/uint for intptr_t/uintptr_t

int/uint aren't considered FFI safe, replace them with the actual type they
represent (i64/u64 or i32/u32). This is a breaking change, but at most a cast
to `uint` or `int` needs to be added.

[breaking-change]
libgreen: use FFI-safe types
Stage #[repr(packed)] in std::rt
iOS compilation fix
Fixed unwinding for iOS

Was broken by Windows adoption
bitv: make benchmarks always return a value

This makes sure that the benchmarked code does not get optimized away.
Also fixed a typo.

Fixes #12118.
arena: fix a typo
bitv: make sure benchmarks run long enough

Previously they were too short (less than 10 ns), so the benchmarker
could not resolve them meaningfully. Now they should run in the order of
100 ns.
fix module wording in guide

@kimundi was a bit worried this was misleading.
Fix FFI guide