Allow lifetime parameters to be inferred

src/librustc/mir/mod.rs

@@ -1555,7 +1555,7 @@ pub struct Statement<'tcx> {
 #[cfg(target_arch = "x86_64")]
 static_assert_size!(Statement<'_>, 56);
 
-impl<'tcx> Statement<'tcx> {
+impl Statement<'_> {
     /// Changes a statement to a nop. This is both faster than deleting instructions and avoids
     /// invalidating statement indices in `Location`s.
     pub fn make_nop(&mut self) {
@@ -1677,7 +1677,7 @@ pub struct InlineAsm<'tcx> {
     pub inputs: Box<[(Span, Operand<'tcx>)]>,
 }
 
-impl<'tcx> Debug for Statement<'tcx> {
+impl Debug for Statement<'_> {
     fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result {
         use self::StatementKind::*;
         match self.kind {
@@ -2047,7 +2047,7 @@ impl<'p, 'tcx> Iterator for ProjectionsIter<'p, 'tcx> {
 
 impl<'p, 'tcx> FusedIterator for ProjectionsIter<'p, 'tcx> {}
 
-impl<'tcx> Debug for Place<'tcx> {
+impl Debug for Place<'_> {
     fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result {
         self.iterate(|_place_base, place_projections| {
             // FIXME: remove this collect once we have migrated to slices

src/librustc_mir/dataflow/move_paths/mod.rs

@@ -240,7 +240,7 @@ impl MovePathLookup {
     // alternative will *not* create a MovePath on the fly for an
     // unknown place, but will rather return the nearest available
     // parent.
-    pub fn find(&self, place_ref: PlaceRef<'cx, 'tcx>) -> LookupResult {
+    pub fn find(&self, place_ref: PlaceRef<'_, '_>) -> LookupResult {
         place_ref.iterate(|place_base, place_projection| {
             let mut result = match place_base {
                 PlaceBase::Local(local) => self.locals[*local],