patch 9.1.1705: time.h include is available on all platforms

Problem:  time.h include is available on all platforms
Solution: Remove ifdef guards and simply include it in all source files,
          get rid of double include in spellfile.c (Damien Lejay).

closes: #18075

Signed-off-by: Damien Lejay <damien@lejay.be>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/memline.c

@@ -44,9 +44,7 @@
 
 #include "vim.h"
 
-#ifndef UNIX		// it's in os_unix.h for Unix
-# include <time.h>
-#endif
+#include <time.h>
 
 #if defined(SASC) || defined(__amigaos4__)
 # include <proto/dos.h>	    // for Open() and Close()

src/spell.c

@@ -60,9 +60,7 @@
 
 #if defined(FEAT_SPELL) || defined(PROTO)
 
-#ifndef UNIX		// it's in os_unix.h for Unix
-# include <time.h>	// for time_t
-#endif
+#include <time.h>
 
 #define REGION_ALL 0xff		// word valid in all regions
 

src/spellfile.c

@@ -241,13 +241,7 @@
 
 #if defined(FEAT_SPELL) || defined(PROTO)
 
-#ifndef UNIX		// it's in os_unix.h for Unix
-# include <time.h>	// for time_t
-#endif
-
-#ifndef UNIX		// it's in os_unix.h for Unix
-# include <time.h>	// for time_t
-#endif
+#include <time.h>	// for time_t
 
 // Special byte values for <byte>.  Some are only used in the tree for
 // postponed prefixes, some only in the other trees.  This is a bit messy...

src/version.c

@@ -724,6 +724,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1705,
 /**/
     1704,
 /**/