vim-patch:9.1.1224: cannot :put while keeping indent (#33076)

Problem:  cannot :put while keeping indent (Peter Aronoff)
Solution: add the :iput ex command (64-bitman)

fixes: vim/vim#16225
closes: vim/vim#16886

e08f10a55c

Cherry-pick test_put.vim changes from patch 8.2.1593.

N/A patches:
vim-patch:9.1.1213: cannot :put while keeping indent
vim-patch:9.1.1215: Patch 9.1.1213 has some issues

Co-authored-by: 64-bitman <60551350+64-bitman@users.noreply.github.com>
Co-authored-by: Hirohito Higashi <h.east.727@gmail.com>

src/nvim/ex_cmds.lua

@@ -1218,6 +1218,12 @@ M.cmds = {
     addr_type = 'ADDR_NONE',
     func = 'ex_intro',
   },
+  {
+    command = 'iput',
+    flags = bit.bor(RANGE, WHOLEFOLD, BANG, REGSTR, TRLBAR, ZEROR, CMDWIN, LOCK_OK, MODIFY),
+    addr_type = 'ADDR_LINES',
+    func = 'ex_iput',
+  },
   {
     command = 'isearch',
     flags = bit.bor(BANG, RANGE, DFLALL, WHOLEFOLD, EXTRA, CMDWIN, LOCK_OK),