vim-patch:8.0.0433: beeps when running tests

Problem:    Quite a few beeps when running tests.
Solution:   Set 'belloff' for these tests. (Christian Brabandt)

c3c766ea8c

src/nvim/testdir/test_alot.vim

@@ -1,6 +1,7 @@
 " A series of tests that can run in one Vim invocation.
 " This makes testing go faster, since Vim doesn't need to restart.
 
+set belloff=all
 source test_assign.vim
 source test_changedtick.vim
 source test_cursor_func.vim

src/nvim/testdir/test_cmdline.vim

@@ -1,5 +1,7 @@
 " Tests for editing the command line.
 
+set belloff=all
+
 func Test_complete_tab()
   call writefile(['testfile'], 'Xtestfile')
   call feedkeys(":e Xtestf\t\r", "tx")

src/nvim/testdir/test_diffmode.vim

@@ -1,4 +1,5 @@
 " Tests for diff mode
+set belloff=all
 
 func Test_diff_fold_sync()
   enew!

src/nvim/testdir/test_digraph.vim

@@ -3,6 +3,7 @@
 if !has("digraphs") || !has("multi_byte")
   finish
 endif
+set belloff=all
 
 func! Put_Dig(chars)
   exe "norm! o\<c-k>".a:chars

src/nvim/testdir/test_normal.vim

@@ -2,6 +2,7 @@
 
 source shared.vim
 
+set belloff=all
 func! Setup_NewWindow()
   10new
   call setline(1, range(1,100))

src/nvim/testdir/test_search.vim

@@ -1,5 +1,6 @@
 " Test for the search command
 
+set belloff=all
 func Test_search_cmdline()
   " See test/functional/legacy/search_spec.lua
   throw 'skipped: Nvim does not support test_disable_char_avail()'

src/nvim/testdir/test_textobjects.vim

@@ -4,6 +4,7 @@ if !has('textobjects')
   finish
 endif
 
+set belloff=all
 function! CpoM(line, useM, expected)
   new
 

src/nvim/testdir/test_undo.vim

@@ -3,6 +3,7 @@
 " undo-able pieces.  Do that by setting 'undolevels'.
 " Also tests :earlier and :later.
 
+set belloff=all
 func Test_undotree()
   exe "normal Aabc\<Esc>"
   set ul=100

src/nvim/testdir/test_usercommands.vim

@@ -1,6 +1,7 @@
 " Tests for user defined commands
 
 " Test for <mods> in user defined commands
+set belloff=all
 function Test_cmdmods()
   let g:mods = ''
 

src/nvim/testdir/test_visual.vim

@@ -3,6 +3,8 @@ if !has('visual')
   finish
 endif
 
+set belloff=all
+
 func Test_block_shift_multibyte()
   " Uses double-wide character.
   if !has('multi_byte')