Auto merge of #149273 - bjorn3:crate_locator_improvements, r=petrochenkov

Don't leak sysroot crates through dependencies

Previously if a dependency of the current crate depended on a sysroot crate, then `extern crate` would in the current crate would pick the first loaded version of said sysroot crate even in case of an ambiguity. This is surprising and brittle. For `-Ldependency=` we already blocked this since rust-lang/rust#110229, but the fix didn't account for sysroot crates.

Should fix rust-lang/rust#147966

Author: bors

src/diagnostics.rs

@@ -3,8 +3,8 @@ use std::num::NonZero;
 use std::sync::Mutex;
 
 use rustc_abi::{Align, Size};
+use rustc_data_structures::fx::{FxBuildHasher, FxHashSet};
 use rustc_errors::{Diag, DiagMessage, Level};
-use rustc_hash::FxHashSet;
 use rustc_span::{DUMMY_SP, Span, SpanData, Symbol};
 
 use crate::borrow_tracker::stacked_borrows::diagnostics::TagHistory;
@@ -899,6 +899,6 @@ pub struct SpanDedupDiagnostic(Mutex<FxHashSet<Span>>);
 
 impl SpanDedupDiagnostic {
     pub const fn new() -> Self {
-        Self(Mutex::new(FxHashSet::with_hasher(rustc_hash::FxBuildHasher)))
+        Self(Mutex::new(FxHashSet::with_hasher(FxBuildHasher)))
     }
 }

src/helpers.rs

@@ -6,7 +6,7 @@ use std::{cmp, iter};
 use rand::RngCore;
 use rustc_abi::{Align, ExternAbi, FieldIdx, FieldsShape, Size, Variants};
 use rustc_apfloat::Float;
-use rustc_hash::FxHashSet;
+use rustc_data_structures::fx::{FxBuildHasher, FxHashSet};
 use rustc_hir::Safety;
 use rustc_hir::def::{DefKind, Namespace};
 use rustc_hir::def_id::{CRATE_DEF_INDEX, CrateNum, DefId, LOCAL_CRATE};
@@ -663,7 +663,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             RejectOpWith::WarningWithoutBacktrace => {
                 // Deduplicate these warnings *by shim* (not by span)
                 static DEDUP: Mutex<FxHashSet<String>> =
-                    Mutex::new(FxHashSet::with_hasher(rustc_hash::FxBuildHasher));
+                    Mutex::new(FxHashSet::with_hasher(FxBuildHasher));
                 let mut emitted_warnings = DEDUP.lock().unwrap();
                 if !emitted_warnings.contains(op_name) {
                     // First time we are seeing this.

src/lib.rs

@@ -58,7 +58,6 @@ extern crate rustc_codegen_ssa;
 extern crate rustc_const_eval;
 extern crate rustc_data_structures;
 extern crate rustc_errors;
-extern crate rustc_hash;
 extern crate rustc_hir;
 extern crate rustc_index;
 extern crate rustc_log;