Rollup merge of #99027 - tmiasko:basic-blocks, r=oli-obk

Replace `Body::basic_blocks()` with field access

Since the refactoring in #98930, it is possible to borrow the basic blocks
independently from other parts of MIR by accessing the `basic_blocks` field
directly.

Replace unnecessary `Body::basic_blocks()` method with a direct field access,
which has an additional benefit of borrowing the basic blocks only.

compiler/rustc_mir_transform/src/const_prop.rs

@@ -131,7 +131,7 @@ impl<'tcx> MirPass<'tcx> for ConstProp {
 
         let dummy_body = &Body::new(
             body.source,
-            body.basic_blocks().clone(),
+            (*body.basic_blocks).clone(),
             body.source_scopes.clone(),
             body.local_decls.clone(),
             Default::default(),