Rollup merge of rust-lang#56561 - Zoxc:too-raw, r=Gankro

Fix bug in from_key_hashed_nocheck

Author: kennytm

src/libstd/collections/hash/map.rs

@@ -11,6 +11,7 @@
 use self::Entry::*;
 use self::VacantEntryState::*;
 
+use intrinsics::unlikely;
 use collections::CollectionAllocErr;
 use cell::Cell;
 use borrow::Borrow;
@@ -1992,6 +1993,9 @@ impl<'a, K, V, S> RawEntryBuilder<'a, K, V, S>
     fn search<F>(self, hash: u64, is_match: F, compare_hashes: bool) -> Option<(&'a K, &'a V)>
         where F: FnMut(&K) -> bool
     {
+        if unsafe { unlikely(self.map.table.size() == 0) } {
+            return None;
+        }
         match search_hashed_nonempty(&self.map.table,
                                      SafeHash::new(hash),
                                      is_match,