vim-patch:8.0.1448: segfault with exception inside :rubyfile command

Problem:    Segmentation fault when Ruby throws an exception inside :rubyfile
            command.
Solution:   Use rb_protect() instead of rb_load_protect(). (ujihisa,
            closes vim/vim#2147, greywolf, closes vim/vim#2512, vim/vim#2511)
37badc898b

src/nvim/testdir/test_ruby.vim

@@ -0,0 +1,59 @@
+" Tests for ruby interface
+
+if !has('ruby')
+  finish
+end
+
+func Test_ruby_change_buffer()
+  call setline(line('$'), ['1 line 1'])
+  ruby Vim.command("normal /^1\n")
+  ruby $curbuf.line = "1 changed line 1"
+  call assert_equal('1 changed line 1', getline('$'))
+endfunc
+
+func Test_ruby_evaluate_list()
+  call setline(line('$'), ['2 line 2'])
+  ruby Vim.command("normal /^2\n")
+  let l = ["abc", "def"]
+  ruby << EOF
+  curline = $curbuf.line_number
+  l = Vim.evaluate("l");
+  $curbuf.append(curline, l.join("\n"))
+EOF
+  normal j
+  .rubydo $_ = $_.gsub(/\n/, '/')
+  call assert_equal('abc/def', getline('$'))
+endfunc
+
+func Test_ruby_evaluate_dict()
+  let d = {'a': 'foo', 'b': 123}
+  redir => l:out
+  ruby d = Vim.evaluate("d"); print d
+  redir END
+  call assert_equal(['{"a"=>"foo", "b"=>123}'], split(l:out, "\n"))
+endfunc
+
+func Test_rubydo()
+  " Check deleting lines does not trigger ml_get error.
+  new
+  call setline(1, ['one', 'two', 'three'])
+  rubydo Vim.command("%d_")
+  bwipe!
+
+  " Check switching to another buffer does not trigger ml_get error.
+  new
+  let wincount = winnr('$')
+  call setline(1, ['one', 'two', 'three'])
+  rubydo Vim.command("new")
+  call assert_equal(wincount + 1, winnr('$'))
+  bwipe!
+  bwipe!
+endfunc
+
+func Test_rubyfile()
+  " Check :rubyfile does not SEGV with Ruby level exception but just fails
+  let tempfile = tempname() . '.rb'
+  call writefile(['raise "vim!"'], tempfile)
+  call assert_fails('rubyfile ' . tempfile)
+  call delete(tempfile)
+endfunc