Auto merge of #83105 - JohnTitor:rollup-tqpm8pb, r=JohnTitor

Rollup of 10 pull requests

Successful merges:

 - #81465 (Add documentation about formatting `Duration` values)
 - #82121 (Implement Extend and FromIterator for OsString)
 - #82617 (Document `everybody_loops`)
 - #82789 (Get with field index from pattern slice instead of directly indexing)
 - #82798 (Rename `rustdoc` to `rustdoc::all`)
 - #82804 (std: Fix a bug on the wasm32-wasi target opening files)
 - #82943 (Demonstrate best practice for feeding stdin of a child processes)
 - #83066 (Add `reverse` search alias for Iterator::rev())
 - #83070 (Update cargo)
 - #83081 (Fix panic message of `assert_failed_inner`)

Failed merges:

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

3 files changed, 22 insertions, 11 deletions

diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index 0a30eda1ec4..341cfa47900 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -712,16 +712,24 @@ pub fn non_durable_rename(src: &Path, dst: &Path) -> std::io::Result<()> {
     std::fs::rename(src, dst)
 }
 
-// Note: Also used by librustdoc, see PR #43348. Consider moving this struct elsewhere.
-//
-// FIXME: Currently the `everybody_loops` transformation is not applied to:
-//  * `const fn`, due to issue #43636 that `loop` is not supported for const evaluation. We are
-//    waiting for miri to fix that.
-//  * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
-//    Solving this may require `!` to implement every trait, which relies on the an even more
-//    ambitious form of the closed RFC #1637. See also [#34511].
-//
-// [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
+/// Replaces function bodies with `loop {}` (an infinite loop). This gets rid of
+/// all semantic errors in the body while still satisfying the return type,
+/// except in certain cases, see below for more.
+///
+/// This pass is known as `everybody_loops`. Very punny.
+///
+/// As of March 2021, `everybody_loops` is only used for the
+/// `-Z unpretty=everybody_loops` debugging option.
+///
+/// FIXME: Currently the `everybody_loops` transformation is not applied to:
+///  * `const fn`; support could be added, but hasn't. Originally `const fn`
+///    was skipped due to issue #43636 that `loop` was not supported for
+///    const evaluation.
+///  * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
+///    Solving this may require `!` to implement every trait, which relies on the an even more
+///    ambitious form of the closed RFC #1637. See also [#34511].
+///
+/// [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
 pub struct ReplaceBodyWithLoop<'a, 'b> {
     within_static_or_const: bool,
     nested_blocks: Option<Vec<ast::Block>>,
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index 9e61c83fda3..408f41e91b0 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -346,6 +346,7 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
         "intra_doc_link_resolution_failure",
         "use `rustdoc::broken_intra_doc_links` instead",
     );
+    store.register_removed("rustdoc", "use `rustdoc::all` instead");
 
     store.register_removed("unknown_features", "replaced by an error");
     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
diff --git a/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
index 3a67eeff92c..8c740a7ec15 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
@@ -1343,7 +1343,9 @@ impl<'p, 'tcx> Fields<'p, 'tcx> {
         match &mut fields {
             Fields::Vec(pats) => {
                 for (i, pat) in new_pats {
-                    pats[i] = pat
+                    if let Some(p) = pats.get_mut(i) {
+                        *p = pat;
+                    }
                 }
             }
             Fields::Filtered { fields, .. } => {