Auto merge of #66944 - Centril:rollup-ojsszx6, r=Centril

Rollup of 7 pull requests

Successful merges:

 - #66346 (Replace .unwrap() with ? in std::os::unix::net)
 - #66789 (rustc: move mir::SourceScopeLocalData to a field of SourceScopeData.)
 - #66850 (rustc: hide HirId's fmt::Debug output from -Z span_free_formats.)
 - #66905 (rustc_plugin: Remove some remaining plugin features)
 - #66907 (rustc: don't just show raw DefIndex's in BrNamed's fmt::Debug impl.)
 - #66918 (Add crc and crypto to target feature whitelist on arm)
 - #66926 (add reusable MachineStop variant to Miri engine error enum)

Failed merges:

r? @ghost

Author: bors

src/doc/rustc/src/lints/listing/warn-by-default.md

@@ -307,18 +307,6 @@ warning: path statement with no effect
   |
 ```
 
-## plugin-as-library
-
-This lint detects when compiler plugins are used as ordinary library in
-non-plugin crate. Some example code that triggers this lint:
-
-```rust,ignore
-#![feature(plugin)]
-#![plugin(macro_crate_test)]
-
-extern crate macro_crate_test;
-```
-
 ## private-in-public
 
 This lint detects private items in public interfaces not caught by the old implementation. Some

src/doc/unstable-book/src/language-features/plugin.md

@@ -21,15 +21,10 @@ the crate attribute `#![plugin(...)]`.  See the
 `rustc_driver::plugin` documentation for more about the
 mechanics of defining and loading a plugin.
 
-If present, arguments passed as `#![plugin(foo(... args ...))]` are not
-interpreted by rustc itself.  They are provided to the plugin through the
-`Registry`'s `args` method.
-
 In the vast majority of cases, a plugin should *only* be used through
 `#![plugin]` and not through an `extern crate` item.  Linking a plugin would
 pull in all of libsyntax and librustc as dependencies of your crate.  This is
-generally unwanted unless you are building another plugin.  The
-`plugin_as_library` lint checks these guidelines.
+generally unwanted unless you are building another plugin.
 
 The usual practice is to put compiler plugins in their own crate, separate from
 any `macro_rules!` macros or ordinary Rust code meant to be used by consumers