Add tests for #2482

Author: topecongiro

rustfmt-core/tests/source/issue-2482/b.rs

@@ -0,0 +1 @@
+pub fn b() {}

rustfmt-core/tests/source/issue-2482/c.rs

@@ -0,0 +1 @@
+pub fn c() {}

rustfmt-core/tests/source/issue-2482/mod.rs

@@ -0,0 +1,7 @@
+// Do not reorder inline modules.
+
+mod c;
+mod a {
+    fn foo() {}
+}
+mod b;

rustfmt-core/tests/target/issue-2482/b.rs

@@ -0,0 +1 @@
+pub fn b() {}

rustfmt-core/tests/target/issue-2482/c.rs

@@ -0,0 +1 @@
+pub fn c() {}

rustfmt-core/tests/target/issue-2482/mod.rs

@@ -0,0 +1,7 @@
+// Do not reorder inline modules.
+
+mod c;
+mod a {
+    fn foo() {}
+}
+mod b;