Add blank lines after module-level // comments.

Similar to the previous commit.

Author: nnethercote

compiler/rustc_hir_analysis/src/check/dropck.rs

@@ -1,6 +1,7 @@
 // FIXME(@lcnr): Move this module out of `rustc_hir_analysis`.
 //
 // We don't do any drop checking during hir typeck.
+
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{codes::*, struct_span_code_err, ErrorGuaranteed};
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;

compiler/rustc_parse/src/parser/expr.rs

@@ -1,4 +1,5 @@
 // ignore-tidy-filelength
+
 use super::diagnostics::SnapshotParser;
 use super::pat::{CommaRecoveryMode, Expected, RecoverColon, RecoverComma};
 use super::ty::{AllowPlus, RecoverQPath, RecoverReturnSign};

library/core/tests/net/parser.rs

@@ -1,4 +1,5 @@
 // FIXME: These tests are all excellent candidates for AFL fuzz testing
+
 use core::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
 use core::str::FromStr;
 

library/core/tests/pin_macro.rs

@@ -1,4 +1,5 @@
 // edition:2021
+
 use core::{
     marker::PhantomPinned,
     mem::{drop as stuff, transmute},

tests/run-make/symlinked-libraries/rmake.rs

@@ -6,6 +6,7 @@
 // See https://github.com/rust-lang/rust/issues/12459
 
 //@ ignore-cross-compile
+
 use run_make_support::{create_symlink, dynamic_lib_name, fs_wrapper, rustc};
 
 fn main() {