Rollup of 24 pull requests

Successful merges:

 - #140459 (Add `read_buf` equivalents for positioned reads)
 - #143725 (core: add Peekable::next_if_map)
 - #145209 (Stabilize `path_add_extension`)
 - #145342 (fix drop scope for `super let` bindings within `if let`)
 - #145750 (raw_vec.rs: Remove superfluous fn alloc_guard)
 - #145827 (On unused binding or binding not present in all patterns, suggest potential typo of unit struct/variant or const)
 - #145932 (Allow `inline(always)` with a target feature behind a unstable feature `target_feature_inline_always`.)
 - #145962 (Ensure we emit an allocator shim when only some crate types need one)
 - #145963 (Add LSX accelerated implementation for source file analysis)
 - #146054 (add `#[must_use]` to `array::repeat`)
 - #146090 (Derive `PartialEq` for `InvisibleOrigin`)
 - #146112 (don't uppercase error messages)
 - #146120 (Correct typo in `rustc_errors` comment)
 - #146124 (Test `rustc-dev` in `distcheck`)
 - #146127 (Rename `ToolRustc` to `ToolRustcPrivate`)
 - #146131 (rustdoc-search: add test case for indexing every item type)
 - #146134 (llvm: nvptx: Layout update to match LLVM)
 - #146136 (docs(std): add missing closing code block fences in doc comments)
 - #146137 (Disallow frontmatter in `--cfg` and `--check-cfg` arguments)
 - #146140 (compiletest: cygwin follows windows in using PATH for dynamic libraries)
 - #146150 (fix(rustdoc): match rustc `--emit` precedence )
 - #146155 (Make bootstrap self test parallel)
 - #146161 ([rustdoc] Uncomment code to add scraped rustdoc examples in loaded paths)
 - #146172 (triagebot: configure some pings when certain attributes are used)

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