Use debug log level for developer oriented logs

The information logged here is of limited general interest, while at the
same times makes it impractical to simply enable logging and share the
resulting logs due to the amount of the output produced.

Reduce log level from info to debug for developer oriented information.

For example, when building cargo, this reduces the amount of logs
generated by `RUSTC_LOG=info cargo build` from 265 MB to 79 MB.

Continuation of changes from 81350.

compiler/rustc_mir/src/transform/inline.rs

@@ -159,7 +159,7 @@ impl Inliner<'tcx> {
         }
     }
 
-    #[instrument(skip(self, caller_body))]
+    #[instrument(level = "debug", skip(self, caller_body))]
     fn is_mir_available(&self, callee: Instance<'tcx>, caller_body: &Body<'tcx>) -> bool {
         match callee.def {
             InstanceDef::Item(_) => {
@@ -258,7 +258,7 @@ impl Inliner<'tcx> {
         None
     }
 
-    #[instrument(skip(self, callee_body))]
+    #[instrument(level = "debug", skip(self, callee_body))]
     fn should_inline(&self, callsite: CallSite<'tcx>, callee_body: &Body<'tcx>) -> bool {
         let tcx = self.tcx;
 

compiler/rustc_mir/src/transform/inline/cycle.rs

@@ -7,7 +7,7 @@ use rustc_middle::ty::{self, subst::SubstsRef, InstanceDef, TyCtxt};
 
 // FIXME: check whether it is cheaper to precompute the entire call graph instead of invoking
 // this query riddiculously often.
-#[instrument(skip(tcx, root, target))]
+#[instrument(level = "debug", skip(tcx, root, target))]
 crate fn mir_callgraph_reachable(
     tcx: TyCtxt<'tcx>,
     (root, target): (ty::Instance<'tcx>, LocalDefId),
@@ -27,7 +27,10 @@ crate fn mir_callgraph_reachable(
         !tcx.is_constructor(root.def_id()),
         "you should not call `mir_callgraph_reachable` on enum/struct constructor functions"
     );
-    #[instrument(skip(tcx, param_env, target, stack, seen, recursion_limiter, caller))]
+    #[instrument(
+        level = "debug",
+        skip(tcx, param_env, target, stack, seen, recursion_limiter, caller)
+    )]
     fn process(
         tcx: TyCtxt<'tcx>,
         param_env: ty::ParamEnv<'tcx>,

compiler/rustc_mir_build/src/thir/pattern/usefulness.rs

@@ -1079,7 +1079,10 @@ impl<'tcx> Witness<'tcx> {
 /// `is_under_guard` is used to inform if the pattern has a guard. If it
 /// has one it must not be inserted into the matrix. This shouldn't be
 /// relied on for soundness.
-#[instrument(skip(cx, matrix, witness_preference, hir_id, is_under_guard, is_top_level))]
+#[instrument(
+    level = "debug",
+    skip(cx, matrix, witness_preference, hir_id, is_under_guard, is_top_level)
+)]
 fn is_useful<'p, 'tcx>(
     cx: &MatchCheckCtxt<'p, 'tcx>,
     matrix: &Matrix<'p, 'tcx>,

compiler/rustc_span/src/hygiene.rs

@@ -1405,8 +1405,8 @@ fn update_disambiguator(expn_id: ExpnId) {
     });
 
     if modified {
-        info!("Set disambiguator for {:?} (hash {:?})", expn_id, first_hash);
-        info!("expn_data = {:?}", expn_id.expn_data());
+        debug!("Set disambiguator for {:?} (hash {:?})", expn_id, first_hash);
+        debug!("expn_data = {:?}", expn_id.expn_data());
 
         // Verify that the new disambiguator makes the hash unique
         #[cfg(debug_assertions)]

compiler/rustc_trait_selection/src/traits/codegen.rs

@@ -91,7 +91,7 @@ pub fn codegen_fulfill_obligation<'tcx>(
         });
         let impl_source = drain_fulfillment_cx_or_panic(&infcx, &mut fulfill_cx, impl_source);
 
-        info!("Cache miss: {:?} => {:?}", trait_ref, impl_source);
+        debug!("Cache miss: {:?} => {:?}", trait_ref, impl_source);
         Ok(impl_source)
     })
 }

compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -647,7 +647,7 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
                 ProcessResult::Unchanged
             }
             Err(selection_err) => {
-                info!("selecting trait at depth {} yielded Err", obligation.recursion_depth);
+                debug!("selecting trait at depth {} yielded Err", obligation.recursion_depth);
 
                 ProcessResult::Error(CodeSelectionError(selection_err))
             }

compiler/rustc_traits/src/dropck_outlives.rs

@@ -80,7 +80,7 @@ fn dropck_outlives<'tcx>(
             let cause = ObligationCause::dummy();
             let mut constraints = DtorckConstraint::empty();
             while let Some((ty, depth)) = ty_stack.pop() {
-                info!(
+                debug!(
                     "{} kinds, {} overflows, {} ty_stack",
                     result.kinds.len(),
                     result.overflows.len(),