patch 8.0.0688: cannot resize the window in a FileType autocommand

Problem:    Cannot resize the window in a FileType autocommand. (Ingo Karkat)
Solution:   Add the CMDWIN flag to :resize. (test by Ingo Karkat,
            closes #1804)
diff --git a/src/ex_cmds.h b/src/ex_cmds.h
index 519cd08..02d5690 100644
--- a/src/ex_cmds.h
+++ b/src/ex_cmds.h
@@ -51,7 +51,9 @@
 #define BUFUNL	      0x20000L	/* accepts unlisted buffer too */
 #define ARGOPT	      0x40000L	/* allow "++opt=val" argument */
 #define SBOXOK	      0x80000L	/* allowed in the sandbox */
-#define CMDWIN	     0x100000L	/* allowed in cmdline window */
+#define CMDWIN	     0x100000L	/* allowed in cmdline window; when missing
+				 * disallows editing another buffer when
+				 * curbuf_lock is set */
 #define MODIFY       0x200000L	/* forbidden in non-'modifiable' buffer */
 #define EXFLAGS      0x400000L	/* allow flags after count in argument */
 #define FILES	(XFILE | EXTRA)	/* multiple extra files allowed */
@@ -1176,7 +1178,7 @@
 			EXTRA|NOTRLCOM|TRLBAR|CMDWIN,
 			ADDR_LINES),
 EX(CMD_resize,		"resize",	ex_resize,
-			RANGE|NOTADR|TRLBAR|WORD1,
+			RANGE|NOTADR|TRLBAR|WORD1|CMDWIN,
 			ADDR_LINES),
 EX(CMD_retab,		"retab",	ex_retab,
 			TRLBAR|RANGE|WHOLEFOLD|DFLALL|BANG|WORD1|CMDWIN|MODIFY,