…as-schievink

Rollup of 14 pull requests

Successful merges:

 - rust-lang#76765 (Make it more clear what an about async fn's returns when referring to what it returns)
 - rust-lang#78574 (Use check-pass instead of build-pass in regions ui test suite)
 - rust-lang#78669 (Use check-pass instead of build-pass in some consts ui test suits)
 - rust-lang#78847 (Assert that a return place is not used for indexing during integration)
 - rust-lang#78854 (Workaround for "could not fully normalize" ICE )
 - rust-lang#78875 (rustc_target: Further cleanup use of target options)
 - rust-lang#78887 (Add comments to explain memory usage optimization)
 - rust-lang#78890 (comment attribution fix)
 - rust-lang#78896 (Clarified description of write! macro)
 - rust-lang#78897 (Add missing newline to error message of the default OOM hook)
 - rust-lang#78898 (add regression test for rust-lang#78892)
 - rust-lang#78908 ((rustdoc) [src] link for types defined by macros shows invocation, not defintion)
 - rust-lang#78910 (Fix links to stabilized versions of some intrinsics)
 - rust-lang#78912 (Add macro test for min-const-generics)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

rustc_target: Fix dash vs underscore mismatches in option names

Fixes rust-lang#78981 (regression from rust-lang#78875, the old option names used dashes)

…lacrum

rustc_target: Further cleanup use of target options

Follow up to rust-lang#77729.

Implements items 2 and 4 from the list in rust-lang#77729 (comment).

The first commit collapses uses of `target.options.foo` into `target.foo`.

The second commit renames some target options to avoid tautology:
`target.target_endian` -> `target.endian`
`target.target_c_int_width` -> `target.c_int_width`
`target.target_os` -> `target.os`
`target.target_env` -> `target.env`
`target.target_vendor` -> `target.vendor`
`target.target_family` -> `target.os_family`
`target.target_mcount` -> `target.mcount`

r? `@Mark-Simulacrum`