Delete query stats

These statistics are computable from the self-profile data and/or ad-hoc
collectable as needed, and in the meantime contribute to rustc bootstrap times.

Author: Mark-Simulacrum

compiler/rustc_interface/src/queries.rs

@@ -403,10 +403,6 @@ impl Compiler {
                 gcx.enter(rustc_query_impl::alloc_self_profile_query_strings);
             }
 
-            if self.session().opts.debugging_opts.query_stats {
-                gcx.enter(rustc_query_impl::print_stats);
-            }
-
             self.session()
                 .time("serialize_dep_graph", || gcx.enter(rustc_incremental::save_dep_graph));
         }

compiler/rustc_interface/src/tests.rs

@@ -684,7 +684,6 @@ fn test_debugging_options_tracking_hash() {
     untracked!(print_type_sizes, true);
     untracked!(proc_macro_backtrace, true);
     untracked!(query_dep_graph, true);
-    untracked!(query_stats, true);
     untracked!(save_analysis, true);
     untracked!(self_profile, SwitchWithOptPath::Enabled(None));
     untracked!(self_profile_events, Some(vec![String::new()]));

compiler/rustc_query_impl/src/lib.rs

@@ -28,9 +28,6 @@ mod plumbing;
 pub use plumbing::QueryCtxt;
 use rustc_query_system::query::*;
 
-mod stats;
-pub use self::stats::print_stats;
-
 mod keys;
 use keys::Key;
 

compiler/rustc_query_impl/src/stats.rs

@@ -1367,8 +1367,6 @@ options! {
         "use the given `.prof` file for sampled profile-guided optimization (also known as AutoFDO)"),
     query_dep_graph: bool = (false, parse_bool, [UNTRACKED],
         "enable queries of the dependency graph for regression testing (default: no)"),
-    query_stats: bool = (false, parse_bool, [UNTRACKED],
-        "print some statistics about the query system (default: no)"),
     randomize_layout: bool = (false, parse_bool, [TRACKED],
         "randomize the layout of types (default: no)"),
     layout_seed: Option<u64> = (None, parse_opt_number, [TRACKED],