This commit normalizes projections which contain opaque types (opaque types
are otherwise linted against, which is would have previously made the
test cases added in this commit fail).

Signed-off-by: David Wood <david@davidtw.co>

…s between OS

…epmaster

Add tests for 'impl Default for [T; N]'

Related: rust-lang#71690.
This pull request adds two tests:
- Even it T::default() panics, no leaks occur.
- [T; 0] is Default even if T is not.

I believe at some moment `Default` impl for arrays will be rewritten to use const generics instead of macros, and these tests will help to prevent behavior changes.

…ies, r=shepmaster

Complete the std::time documentation to warn about the inconsistencies between OS

Fix for rust-lang#48980.

I put the new documentation in `src/libstd/time.rs` at the module-level because it affects all types, even the one that are not directly system dependents if they are used with affected types, but there may be a better place for it.

Fix link error with #[thread_local] introduced by rust-lang#71192

r? @oli-obk

Ensure std benchmarks get tested.

This ensures that the std benchmarks don't break in the future. Currently they aren't compiled or tested on CI, so they can easily bitrot.  Testing a benchmark runs it with one iteration. Adding these should only add a few seconds to CI.

Closes rust-lang#54176
Closes rust-lang#61913

…in-projections, r=estebank

lint: normalize projections using opaque types

Fixes rust-lang#73251.

This PR normalizes projections which use opaque types (opaque types are otherwise linted against, which is would have previously made the test cases added in this PR fail).