tests: Add an integration test for static arrays.

Turns out they were broken before
rust-lang#456.

Let's test it so it doesn't regress.

Author: emilio

bindgen-integration/cpp/Test.cc

@@ -1,5 +1,12 @@
 #include "Test.h"
 
+const int Test::COUNTDOWN[] = { 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 };
+const int* Test::COUNTDOWN_PTR = Test::COUNTDOWN;
+
+const int* Test::countdown() {
+  return COUNTDOWN;
+}
+
 const char* Test::name() {
   return "Test";
 }

bindgen-integration/cpp/Test.h

@@ -7,6 +7,10 @@ class Test {
   static const char* name();
   Test(int foo);
   Test(double foo);
+
+  static const int COUNTDOWN[];
+  static const int* COUNTDOWN_PTR;
+  static const int* countdown();
 };
 
 namespace testing {

bindgen-integration/src/lib.rs

@@ -3,6 +3,31 @@ mod bindings {
 }
 
 use std::ffi::CStr;
+use std::os::raw::c_int;
+
+#[test]
+fn test_static_array() {
+    let mut test = unsafe { bindings::Test_COUNTDOWN.as_ptr() };
+    let expected = unsafe { bindings::Test_countdown()};
+    let also_expected = unsafe { bindings::Test_COUNTDOWN_PTR };
+    assert!(!test.is_null());
+    assert_eq!(also_expected, expected, "Pointer value was bogus");
+    assert_eq!(test, also_expected, "Array value was bogus");
+
+    println!("Test: {:?}", test);
+
+    let mut expected = 10;
+    unsafe {
+        loop {
+            assert_eq!(*test, expected);
+            if *test == 0 {
+                break;
+            }
+            test = test.offset(1);
+            expected -= 1;
+        }
+    }
+}
 
 #[test]
 fn test_static_method() {