Metadata collection: Refining the implementation

Author: xFrednet

.gitignore

@@ -29,7 +29,7 @@ out
 
 # gh pages docs
 util/gh-pages/lints.json
-**/metadata_collection.json
+# **/metadata_collection.json
 
 # rustfmt backups
 *.rs.bk

clippy_lints/src/slow_vector_initialization.rs

@@ -7,7 +7,7 @@ use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_block, walk_expr, walk_stmt, NestedVisitorMap, Visitor};
 use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, HirId, PatKind, QPath, Stmt, StmtKind};
-use rustc_lint::{LateContext, LateLintPass, Lint};
+use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::sym;