patch 8.0.1302: 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 #2326)
diff --git a/src/testdir/test_erasebackword.vim b/src/testdir/test_erasebackword.vim
new file mode 100644
index 0000000..098d6ed
--- /dev/null
+++ b/src/testdir/test_erasebackword.vim
@@ -0,0 +1,25 @@
+
+func Test_erasebackword()
+  if !has('multi_byte')
+    return
+  endif
+
+  set encoding=utf-8
+  enew
+
+  exe "normal o wwwこんにちわ世界ワールドvim \<C-W>"
+  call assert_equal(' wwwこんにちわ世界ワールド', getline('.'))
+  exe "normal o wwwこんにちわ世界ワールドvim \<C-W>\<C-W>"
+  call assert_equal(' wwwこんにちわ世界', getline('.'))
+  exe "normal o wwwこんにちわ世界ワールドvim \<C-W>\<C-W>\<C-W>"
+  call assert_equal(' wwwこんにちわ', getline('.'))
+  exe "normal o wwwこんにちわ世界ワールドvim \<C-W>\<C-W>\<C-W>\<C-W>"
+  call assert_equal(' www', getline('.'))
+  exe "normal o wwwこんにちわ世界ワールドvim \<C-W>\<C-W>\<C-W>\<C-W>\<C-W>"
+  call assert_equal(' ', getline('.'))
+  exe "normal o wwwこんにちわ世界ワールドvim \<C-W>\<C-W>\<C-W>\<C-W>\<C-W>\<C-W>"
+  call assert_equal('', getline('.'))
+
+  enew!
+  set encoding&
+endfunc