vim-patch:7.4.{592,596,632}: Mark as NA

Original commit message for patch 7.4.592:

Problem:    When doing ":e foobar" when already editing "foobar" and 'buftype'
            is "nofile" the buffer is cleared. (Xavier de Gaye)
Solution:   Do no clear the buffer.

https://github.com/vim/vim/commit/v7-4-592

The change in this patch was amended in patch 7.4.596 to fix an #ifdef
problem, but soon after, in patch 7.4.632, it was reverted wholesale.

See https://groups.google.com/d/msg/vim_dev/SWw5znc3W-8/TDjkUVYfABIJ

src/nvim/version.c

@@ -151,7 +151,7 @@ static int included_patches[] = {
   //635,
   //634,
   633,
-  //632,
+  //632 NA
   //631,
   630,
   //629,
@@ -187,11 +187,11 @@ static int included_patches[] = {
   599,
   //598,
   //597,
-  //596,
+  //596 NA
   595,
   //594,
   //593,
-  //592,
+  //592 NA
   //591 NA
   590,
   //589 NA