Auto merge of rust-lang#139536 - matthiaskrgr:rollup-j6goald, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#139476 (rm `RegionInferenceContext::var_infos`)
 - rust-lang#139485 (compiletest: Stricter parsing for diagnostic kinds)
 - rust-lang#139491 (Update books)
 - rust-lang#139500 (document panic behavior of Vec::resize and Vec::resize_with)
 - rust-lang#139501 (Fix stack overflow in exhaustiveness due to recursive HIR opaque hidden types)
 - rust-lang#139504 (add missing word in doc comment)
 - rust-lang#139509 (clean: remove Deref<Target=RegionKind> impl for Region and use `.kind()`)

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

Author: bors

Diff for: compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -406,8 +406,8 @@ impl<'tcx> TypeOpInfo<'tcx> for crate::type_check::InstantiateOpaqueType<'tcx> {
             // started MIR borrowchecking with, so the region
             // constraints have already been taken. Use the data from
             // our `mbcx` instead.
-            |vid| mbcx.regioncx.var_infos[vid].origin,
-            |vid| mbcx.regioncx.var_infos[vid].universe,
+            |vid| RegionVariableOrigin::Nll(mbcx.regioncx.definitions[vid].origin),
+            |vid| mbcx.regioncx.definitions[vid].universe,
         )
     }
 }
@@ -487,7 +487,7 @@ fn try_extract_error_from_region_constraints<'a, 'tcx>(
     let (sub_region, cause) = info?;
 
     debug!(?sub_region, "cause = {:#?}", cause);
-    let error = match (error_region, *sub_region) {
+    let error = match (error_region, sub_region.kind()) {
         (Some(error_region), ty::ReVar(vid)) => RegionResolutionError::SubSupConflict(
             vid,
             region_var_origin(vid),

Diff for: compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -8,9 +8,7 @@ use rustc_errors::{Applicability, Diag, EmissionGuarantee, MultiSpan, listify};
 use rustc_hir::def::{CtorKind, Namespace};
 use rustc_hir::{self as hir, CoroutineKind, LangItem};
 use rustc_index::IndexSlice;
-use rustc_infer::infer::{
-    BoundRegionConversionTime, NllRegionVariableOrigin, RegionVariableOrigin,
-};
+use rustc_infer::infer::{BoundRegionConversionTime, NllRegionVariableOrigin};
 use rustc_infer::traits::SelectionError;
 use rustc_middle::bug;
 use rustc_middle::mir::{
@@ -587,7 +585,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         // this by hooking into the pretty printer and telling it to label the
         // lifetimes without names with the value `'0`.
         if let ty::Ref(region, ..) = ty.kind() {
-            match **region {
+            match region.kind() {
                 ty::ReBound(_, ty::BoundRegion { kind: br, .. })
                 | ty::RePlaceholder(ty::PlaceholderRegion {
                     bound: ty::BoundRegion { kind: br, .. },
@@ -607,7 +605,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         let mut printer = ty::print::FmtPrinter::new(self.infcx.tcx, Namespace::TypeNS);
 
         let region = if let ty::Ref(region, ..) = ty.kind() {
-            match **region {
+            match region.kind() {
                 ty::ReBound(_, ty::BoundRegion { kind: br, .. })
                 | ty::RePlaceholder(ty::PlaceholderRegion {
                     bound: ty::BoundRegion { kind: br, .. },
@@ -633,9 +631,8 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
     ) {
         let predicate_span = path.iter().find_map(|constraint| {
             let outlived = constraint.sub;
-            if let Some(origin) = self.regioncx.var_infos.get(outlived)
-                && let RegionVariableOrigin::Nll(NllRegionVariableOrigin::Placeholder(_)) =
-                    origin.origin
+            if let Some(origin) = self.regioncx.definitions.get(outlived)
+                && let NllRegionVariableOrigin::Placeholder(_) = origin.origin
                 && let ConstraintCategory::Predicate(span) = constraint.category
             {
                 Some(span)