Add test case for issue 5568

Author: ytmimi

tests/target/issue-5568.rs

@@ -0,0 +1,14 @@
+// rustfmt-max_width: 119
+// rustfmt-format_code_in_doc_comments: true
+
+mod libs {
+    fn mrbgems_sources() {
+        [
+            "mrbgems/mruby-compiler/core/codegen.c", // Ruby parser and bytecode generation
+            "mrbgems/mruby-compiler/core/y.tab.c",   // Ruby parser and bytecode generation
+            "mrbgems/mruby-metaprog/src/metaprog.c", // APIs on Kernel and Module for accessing classes and variables
+            "mrbgems/mruby-method/src/method.c",     // `Method`, `UnboundMethod`, and method APIs on Kernel and Module
+            "mrbgems/mruby-pack/src/pack.c",         // Array#pack and String#unpack
+        ]
+    }
+}