add a test case for issue #2695

Author: yshui

Diff for: bindgen-tests/tests/expectations/tests/issue-2695.rs

@@ -0,0 +1,10 @@
+// bindgen-flags: --explicit-padding
+
+#pragma pack(2)
+
+struct Test {
+        unsigned long x;
+        char a;
+        char b;
+        char c;
+};