Resolve wildcard_imports pedantic clippy lint

    error: usage of wildcard import
     --> tests/test_size.rs:5:5
      |
    5 | use syn::*;
      |     ^^^^^^ help: try: `syn::{Expr, Item, Lit, Pat, Type}`
      |
      = note: `-D clippy::wildcard-imports` implied by `-D clippy::pedantic`
      = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports

    error: usage of wildcard import
       --> tests/test_precedence.rs:350:9
        |
    350 |     use syn::fold::*;
        |         ^^^^^^^^^^^^ help: try: `syn::fold::{Fold, fold_expr, fold_generic_argument, fold_generic_method_argument}`
        |
        = note: `-D clippy::wildcard-imports` implied by `-D clippy::pedantic`
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports

    error: usage of wildcard import
       --> tests/test_precedence.rs:351:9
        |
    351 |     use syn::*;
        |         ^^^^^^ help: try: `syn::{Expr, ExprParen, GenericArgument, GenericMethodArgument, Pat, Stmt, Type, token}`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports

    error: usage of wildcard import
       --> tests/test_precedence.rs:427:9
        |
    427 |     use syn::fold::*;
        |         ^^^^^^^^^^^^ help: try: `syn::fold::Fold`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports

    error: usage of wildcard import
       --> tests/test_precedence.rs:429:9
        |
    429 |     use syn::*;
        |         ^^^^^^ help: try: `syn::{Expr, ExprTuple, token}`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports

tests/test_precedence.rs

@@ -5,8 +5,7 @@
     clippy::explicit_deref_methods,
     clippy::if_then_panic,
     clippy::match_wildcard_for_single_variants,
-    clippy::too_many_lines,
-    clippy::wildcard_imports
+    clippy::too_many_lines
 )]
 
 //! The tests in this module do the following:
@@ -347,8 +346,8 @@ fn librustc_brackets(mut librustc_expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
 /// reveal the precedence of the parsed expressions, and produce a stringified
 /// form of the resulting expression.
 fn syn_brackets(syn_expr: syn::Expr) -> syn::Expr {
-    use syn::fold::*;
-    use syn::*;
+    use syn::fold::{fold_expr, fold_generic_argument, fold_generic_method_argument, Fold};
+    use syn::{token, Expr, ExprParen, GenericArgument, GenericMethodArgument, Pat, Stmt, Type};
 
     struct ParenthesizeEveryExpr;
     impl Fold for ParenthesizeEveryExpr {
@@ -424,9 +423,9 @@ fn syn_brackets(syn_expr: syn::Expr) -> syn::Expr {
 
 /// Walk through a crate collecting all expressions we can find in it.
 fn collect_exprs(file: syn::File) -> Vec<syn::Expr> {
-    use syn::fold::*;
+    use syn::fold::Fold;
     use syn::punctuated::Punctuated;
-    use syn::*;
+    use syn::{token, Expr, ExprTuple};
 
     struct CollectExprs(Vec<Expr>);
     impl Fold for CollectExprs {

tests/test_size.rs

@@ -1,8 +1,7 @@
 #![cfg(target_pointer_width = "64")]
-#![allow(clippy::wildcard_imports)]
 
 use std::mem;
-use syn::*;
+use syn::{Expr, Item, Lit, Pat, Type};
 
 #[test]
 fn test_expr_size() {