std: reword some comments

lib/std/array_hash_map.zig

@@ -728,7 +728,7 @@ pub fn ArrayHashMapUnmanaged(
                 }
 
                 const index = self.entries.addOneAssumeCapacity();
-                // unsafe indexing because the length changed
+                // The slice length changed, so we directly index the pointer.
                 if (store_hash) hashes_array.ptr[index] = h;
 
                 return GetOrPutResult{

lib/std/array_list.zig

@@ -501,8 +501,7 @@ pub fn ArrayListAligned(comptime T: type, comptime alignment: ?u29) type {
         /// Returns a slice of all the items plus the extra capacity, whose memory
         /// contents are `undefined`.
         pub fn allocatedSlice(self: Self) Slice {
-            // For a nicer API, `items.len` is the length, not the capacity.
+            // `items.len` is the length, not the capacity.
-            // This requires "unsafe" slicing.
             return self.items.ptr[0..self.capacity];
         }
 
@@ -1010,8 +1009,8 @@ pub fn ArrayListAlignedUnmanaged(comptime T: type, comptime alignment: ?u29) typ
             return self.pop();
         }
 
-        /// For a nicer API, `items.len` is the length, not the capacity.
+        /// Returns a slice of all the items plus the extra capacity, whose memory
-        /// This requires "unsafe" slicing.
+        /// contents are `undefined`.
         pub fn allocatedSlice(self: Self) Slice {
             return self.items.ptr[0..self.capacity];
         }