Rollup merge of #76890 - matthiaskrgr:matches_simpl, r=lcnr

use matches!() macro for simple if let conditions

compiler/rustc_mir/src/transform/promote_consts.rs

@@ -92,7 +92,7 @@ pub enum TempState {
 impl TempState {
     pub fn is_promotable(&self) -> bool {
         debug!("is_promotable: self={:?}", self);
-        if let TempState::Defined { .. } = *self { true } else { false }
+        matches!(self, TempState::Defined { .. } )
     }
 }
 

compiler/rustc_mir/src/transform/simplify.rs

@@ -281,8 +281,7 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> {
 
     fn strip_nops(&mut self) {
         for blk in self.basic_blocks.iter_mut() {
-            blk.statements
-                .retain(|stmt| if let StatementKind::Nop = stmt.kind { false } else { true })
+            blk.statements.retain(|stmt| !matches!(stmt.kind, StatementKind::Nop))
         }
     }
 }