patch 8.0.1271: still too many old style tests

Problem:    Still too many old style tests.
Solution:   Convert a few more tests to new style. (Yegappan Lakshmanan,
            closes #2290)

src/testdir/test_search.vim

@@ -697,3 +697,18 @@ endfunc
 func Test_search_undefined_behaviour2()
   call search("\%UC0000000")
 endfunc
+
+" Test for search('multi-byte char', 'bce')
+func Test_search_multibyte()
+  if !has('multi_byte')
+    return
+  endif
+  let save_enc = &encoding
+  set encoding=utf8
+  enew!
+  call append('$', 'Ａ')
+  call cursor(2, 1)
+  call assert_equal(2, search('Ａ', 'bce', line('.')))
+  enew!
+  let &encoding = save_enc
+endfunc