Update runtime files

runtime/pack/dist/opt/termdebug/plugin/termdebug.vim

@@ -2,7 +2,7 @@
 "
 " Author: Bram Moolenaar
 " Copyright: Vim license applies, see ":help license"
-" Last Change: 2020 Feb 19
+" Last Change: 2020 May 22
 "
 " WORK IN PROGRESS - Only the basics work
 " Note: On MS-Windows you need a recent version of gdb.  The one included with
@@ -657,8 +657,10 @@ func s:InstallCommands()
   command Source call s:GotoSourcewinOrCreateIt()
   command Winbar call s:InstallWinbar()
 
-  " TODO: can the K mapping be restored?
-  nnoremap K :Evaluate<CR>
+  if !exists('g:termdebug_map_K') || g:termdebug_map_K
+    let s:k_map_saved = maparg('K', 'n', 0, 1)
+    nnoremap K :Evaluate<CR>
+  endif
 
   if has('menu') && &mouse != ''
     call s:InstallWinbar()
@@ -708,7 +710,10 @@ func s:DeleteCommands()
   delcommand Source
   delcommand Winbar
 
-  nunmap K
+  if exists('s:k_map_saved')
+    call mapset('n', 0, s:k_map_saved)
+    unlet s:k_map_saved
+  endif
 
   if has('menu')
     " Remove the WinBar entries from all windows where it was added.