More review feedback

* Store the local crates in an Rc<[CrateNum]>
* Move all the allocation history into Stacks
* Clean up the implementation of get_logs_relevant_to a bit

src/helpers.rs

@@ -1,5 +1,6 @@
 use std::mem;
 use std::num::NonZeroUsize;
+use std::rc::Rc;
 use std::time::Duration;
 
 use log::trace;
@@ -797,7 +798,7 @@ pub fn isolation_abort_error(name: &str) -> InterpResult<'static> {
 
 /// Retrieve the list of local crates that should have been passed by cargo-miri in
 /// MIRI_LOCAL_CRATES and turn them into `CrateNum`s.
-pub fn get_local_crates(tcx: &TyCtxt<'_>) -> Vec<CrateNum> {
+pub fn get_local_crates(tcx: &TyCtxt<'_>) -> Rc<[CrateNum]> {
     // Convert the local crate names from the passed-in config into CrateNums so that they can
     // be looked up quickly during execution
     let local_crate_names = std::env::var("MIRI_LOCAL_CRATES")
@@ -811,7 +812,7 @@ pub fn get_local_crates(tcx: &TyCtxt<'_>) -> Vec<CrateNum> {
             local_crates.push(crate_num);
         }
     }
-    local_crates
+    Rc::from(local_crates.as_slice())
 }
 
 /// Formats an AllocRange like [0x1..0x3], for use in diagnostics.

src/machine.rs

@@ -6,6 +6,7 @@ use std::cell::RefCell;
 use std::collections::HashSet;
 use std::fmt;
 use std::num::NonZeroU64;
+use std::rc::Rc;
 use std::time::Instant;
 
 use rand::rngs::StdRng;
@@ -273,7 +274,7 @@ pub struct Evaluator<'mir, 'tcx> {
     pub(crate) backtrace_style: BacktraceStyle,
 
     /// Crates which are considered local for the purposes of error reporting.
-    pub(crate) local_crates: Vec<CrateNum>,
+    pub(crate) local_crates: Rc<[CrateNum]>,
 
     /// Mapping extern static names to their base pointer.
     extern_statics: FxHashMap<Symbol, Pointer<Tag>>,
@@ -307,7 +308,6 @@ impl<'mir, 'tcx> Evaluator<'mir, 'tcx> {
                 config.tracked_pointer_tags.clone(),
                 config.tracked_call_ids.clone(),
                 config.tag_raw,
-                local_crates.clone(),
             )))
         } else {
             None
@@ -575,6 +575,7 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'mir, 'tcx> {
                 stacked_borrows,
                 kind,
                 &ecx.machine.threads,
+                ecx.machine.local_crates.clone(),
             ))
         } else {
             None