patch 9.0.1426: indent wrong after "export namespace" in C++

Problem:    Indent wrong after "export namespace" in C++.
Solution:   Skip over "inline" and "export" in any order. (Virginia Senioria,
            closes #12134, closes #12133)
diff --git a/src/testdir/test_cindent.vim b/src/testdir/test_cindent.vim
index 96e99ac..d27adbc 100644
--- a/src/testdir/test_cindent.vim
+++ b/src/testdir/test_cindent.vim
@@ -4406,6 +4406,18 @@
   inline/* test */namespace {
     111111111111111111;
   }
+  export namespace {
+    111111111111111111;
+  }
+  export inline namespace {
+    111111111111111111;
+  }
+  export/* test */inline namespace {
+    111111111111111111;
+  }
+  inline export namespace {
+    111111111111111111;
+  }
 
   /* invalid namespaces use block indent */
   namespace test test2 {
@@ -4509,6 +4521,18 @@
   inline/* test */namespace {
   111111111111111111;
   }
+  export namespace {
+  111111111111111111;
+  }
+  export inline namespace {
+  111111111111111111;
+  }
+  export/* test */inline namespace {
+  111111111111111111;
+  }
+  inline export namespace {
+  111111111111111111;
+  }
 
   /* invalid namespaces use block indent */
   namespace test test2 {