Remove Bucket and RawTable that are hard to use safely

This removes the following methods in favor of better alternatives:
- `RawTable::erase_no_drop` => Use `RawTable::erase` or
  `RawTable::remove` instead.
- `Bucket::read` => Use `RawTable::remove` instead.
- `Bucket::drop` => Use `RawTable::erase` instead.
- `Bucket::write` => Use `Bucket::as_mut` instead.

Author: Amanieu

src/raw/mod.rs

@@ -340,15 +340,15 @@ impl<T> Bucket<T> {
         }
     }
     #[cfg_attr(feature = "inline-more", inline)]
-    pub unsafe fn drop(&self) {
+    unsafe fn drop(&self) {
         self.as_ptr().drop_in_place();
     }
     #[inline]
-    pub unsafe fn read(&self) -> T {
+    unsafe fn read(&self) -> T {
         self.as_ptr().read()
     }
     #[inline]
-    pub unsafe fn write(&self, val: T) {
+    unsafe fn write(&self, val: T) {
         self.as_ptr().write(val);
     }
     #[inline]
@@ -550,8 +550,7 @@ impl<T, A: Allocator + Clone> RawTable<T, A> {
 
     /// Erases an element from the table without dropping it.
     #[cfg_attr(feature = "inline-more", inline)]
-    #[deprecated(since = "0.8.1", note = "use erase or remove instead")]
-    pub unsafe fn erase_no_drop(&mut self, item: &Bucket<T>) {
+    unsafe fn erase_no_drop(&mut self, item: &Bucket<T>) {
         let index = self.bucket_index(item);
         self.table.erase(index);
     }