Avoid unnecessary allocations

1. Reserve `store.late_passes` with 320 and `store.early_passes` with 64, this leaves us some leeway for adding new passes.
2. Add [env] with some MALLOC_CONF for mainly for faster testing, but to also optimize in profiling.

;Add comment

Author: blyxyas

.cargo/config.toml

@@ -23,3 +23,7 @@ split-debuginfo = "unpacked"
 rustflags = ["--remap-path-prefix", "=clippy_dev"]
 [profile.dev.package.lintcheck]
 rustflags = ["--remap-path-prefix", "=lintcheck"]
+
+# Configure malloc for faster compiling Clippy itself
+[env]
+MALLOC_CONF = "percpu_arena:phycpu,metadata_thp:always,dirty_decay_ms:300,muzzy_decay_ms:300"

clippy_lints/src/lib.rs

@@ -579,6 +579,10 @@ fn register_categories(store: &mut rustc_lint::LintStore) {
 /// Used in `./src/driver.rs`.
 #[expect(clippy::too_many_lines)]
 pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
+    // Avoid unnecessary reallocations
+    store.late_passes.reserve(320);
+    store.early_passes.reserve(64);
+
     register_categories(store);
 
     for (old_name, new_name) in deprecated_lints::RENAMED {