Auto merge of #96214 - Dylan-DPC:rollup-a5b4fow, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #94493 (Improved diagnostic on failure to meet send bound on future in a foreign crate)
 - #95809 (Fix typo in bootstrap.py)
 - #96086 (Remove `--extern-location` and all associated code)
 - #96089 (`alloc`: make `vec!` unavailable under `no_global_oom_handling`)
 - #96122 (Fix an invalid error for a suggestion to add a slice in pattern-matching)
 - #96142 (Stop using CRATE_DEF_INDEX outside of metadata encoding.)

Failed merges:

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

1 files changed, 13 insertions, 2 deletions

diff --git a/compiler/rustc_span/src/def_id.rs b/compiler/rustc_span/src/def_id.rs
index 6d1b36796d8..d5f806308cf 100644
--- a/compiler/rustc_span/src/def_id.rs
+++ b/compiler/rustc_span/src/def_id.rs
@@ -283,8 +283,19 @@ impl DefId {
         self.as_local().unwrap_or_else(|| panic!("DefId::expect_local: `{:?}` isn't local", self))
     }
 
+    #[inline]
+    pub fn is_crate_root(self) -> bool {
+        self.index == CRATE_DEF_INDEX
+    }
+
+    #[inline]
+    pub fn as_crate_root(self) -> Option<CrateNum> {
+        if self.is_crate_root() { Some(self.krate) } else { None }
+    }
+
+    #[inline]
     pub fn is_top_level_module(self) -> bool {
-        self.is_local() && self.index == CRATE_DEF_INDEX
+        self.is_local() && self.is_crate_root()
     }
 }
 
@@ -357,7 +368,7 @@ impl LocalDefId {
 
     #[inline]
     pub fn is_top_level_module(self) -> bool {
-        self.local_def_index == CRATE_DEF_INDEX
+        self == CRATE_DEF_ID
     }
 }