dbg: move to sub functions for easier filtering tracing

Author: tesuji

compiler/rustc_mir_transform/src/gvn.rs

@@ -138,7 +138,7 @@ fn propagate_ssa<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
                     let value = state.simplify_rvalue(rvalue, location);
                     // FIXME(#112651) `rvalue` may have a subtype to `local`. We can only mark `local` as
                     // reusable if we have an exact type match.
-                    if state.local_decls[local].ty != rvalue.ty(state.local_decls, tcx) {
+                    if state.local_decls[local].ty != rvalue.ty(state.local_decls, state.tcx) {
                         return;
                     }
                     value

compiler/rustc_mir_transform/src/ssa.rs

@@ -147,6 +147,7 @@ impl SsaLocals {
         })
     }
 
+    #[instrument(level = "trace", skip_all)]
     pub fn for_each_assignment_mut<'tcx>(
         &self,
         basic_blocks: &mut IndexSlice<BasicBlock, BasicBlockData<'tcx>>,