Rollup merge of #58553 - scottmcm:more-ihle, r=Centril

Use more impl header lifetime elision

Inspired by seeing explicit lifetimes on these two:

- https://doc.rust-lang.org/nightly/std/slice/struct.Iter.html#impl-FusedIterator
- https://doc.rust-lang.org/nightly/std/primitive.u32.html#impl-Not

And a follow-up to https://github.com/rust-lang/rust/pull/54687, that started using IHLE in libcore.

Most of the changes in here fall into two big categories:

- Removing lifetimes from common traits that can essentially never user a lifetime from an input (particularly `Drop`, `Debug`, and `Clone`)

- Forwarding impls that are only possible because the lifetime doesn't matter (like `impl<R: Read + ?Sized> Read for &mut R`)

I omitted things that seemed like they could be more controversial, like the handful of iterators that have a `Item: 'static` despite the iterator having a lifetime or the `PartialEq` implementations [where the flipped one cannot elide the lifetime](https://internals.rust-lang.org/t/impl-type-parameter-aliases/9403/2?u=scottmcm).

I also removed two lifetimes that turned out to be completely unused; see https://github.com/rust-lang/rust/issues/41960#issuecomment-464557423

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libstd/io/cursor.rs b/src/libstd/io/cursor.rs
index b205f788838..758d8568672 100644
--- a/src/libstd/io/cursor.rs
+++ b/src/libstd/io/cursor.rs
@@ -279,7 +279,7 @@ fn vec_write(pos_mut: &mut u64, vec: &mut Vec<u8>, buf: &[u8]) -> io::Result<usi
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a> Write for Cursor<&'a mut [u8]> {
+impl Write for Cursor<&mut [u8]> {
     #[inline]
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         slice_write(&mut self.pos, self.inner, buf)
@@ -288,7 +288,7 @@ impl<'a> Write for Cursor<&'a mut [u8]> {
 }
 
 #[stable(feature = "cursor_mut_vec", since = "1.25.0")]
-impl<'a> Write for Cursor<&'a mut Vec<u8>> {
+impl Write for Cursor<&mut Vec<u8>> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         vec_write(&mut self.pos, self.inner, buf)
     }