transpile: simplify import_type

Author: fw-immunant

c2rust-transpile/src/translator/mod.rs

@@ -5366,19 +5366,13 @@ impl<'c> Translation<'c> {
     }
 
     fn import_type(&self, ctype: CTypeId) {
-        for Import {
-            decl_id,
-            ident_name,
-        } in self.imports_for_type(ctype)
-        {
-            self.add_import(decl_id, &ident_name)
-        }
+        self.add_imports(&self.imports_for_type(ctype))
     }
 
-    fn imports_for_type(&self, ctype: CTypeId) -> Vec<Import> {
+    fn imports_for_type(&self, ctype: CTypeId) -> IndexSet<Import> {
         use self::CTypeKind::*;
 
-        let mut imports = vec![];
+        let mut imports = Default::default();
 
         let type_kind = &self.ast_context[ctype].kind;
         match type_kind {
@@ -5417,7 +5411,7 @@ impl<'c> Translation<'c> {
                     .borrow()
                     .resolve_decl_name(decl_id)
                     .expect("Expected decl name");
-                imports.push(Import {
+                imports.insert(Import {
                     decl_id,
                     ident_name,
                 });