Remove in_band_lifetimes from rustc_mir_transform

This one is a heavy `'tcx` user.

Two interesting ones:

This one had the `'tcx` declared on the function, despite the trait taking a `'tcx`:
```diff
-impl Visitor<'_> for UsedLocals {
+impl<'tcx> Visitor<'tcx> for UsedLocals {
     fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
```

This one use in-band for one, and underscore for the other:
```diff
-pub fn remove_dead_blocks(tcx: TyCtxt<'tcx>, body: &mut Body<'_>) {
+pub fn remove_dead_blocks<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
```

compiler/rustc_mir_transform/src/coverage/graph.rs

@@ -27,7 +27,7 @@ pub(super) struct CoverageGraph {
 }
 
 impl CoverageGraph {
-    pub fn from_mir(mir_body: &mir::Body<'tcx>) -> Self {
+    pub fn from_mir(mir_body: &mir::Body<'_>) -> Self {
         let (bcbs, bb_to_bcb) = Self::compute_basic_coverage_blocks(mir_body);
 
         // Pre-transform MIR `BasicBlock` successors and predecessors into the BasicCoverageBlock
@@ -74,7 +74,7 @@ impl CoverageGraph {
     }
 
     fn compute_basic_coverage_blocks(
-        mir_body: &mir::Body<'tcx>,
+        mir_body: &mir::Body<'_>,
     ) -> (
         IndexVec<BasicCoverageBlock, BasicCoverageBlockData>,
         IndexVec<BasicBlock, Option<BasicCoverageBlock>>,
@@ -267,7 +267,7 @@ impl graph::WithSuccessors for CoverageGraph {
     }
 }
 
-impl graph::GraphPredecessors<'graph> for CoverageGraph {
+impl<'graph> graph::GraphPredecessors<'graph> for CoverageGraph {
     type Item = BasicCoverageBlock;
     type Iter = std::iter::Copied<std::slice::Iter<'graph, BasicCoverageBlock>>;
 }