patch 8.0.1608: Win32: directx not enabled by default

Problem:    Win32: directx not enabled by default.
Solution:   Change Makefile to enable directx by default. (Ken Takata)

runtime/doc/various.txt

@@ -352,7 +352,7 @@ N  *+dialog_con*	Support for |:confirm| with console dialog.
 N  *+dialog_con_gui*	Support for |:confirm| with GUI and console dialog.
 N  *+diff*		|vimdiff| and 'diff'
 N  *+digraphs*		|digraphs| *E196*
-m  *+directx*		Win32 GUI only: DirectX and |'renderoptions'|
+   *+directx*		Win32 GUI only: DirectX and |'renderoptions'|
    *+dnd*		Support for DnD into the "~ register |quote_~|.
 B  *+emacs_tags*	|emacs-tags| files
 N  *+eval*		expression evaluation |eval.txt|

src/Make_cyg_ming.mak

@@ -20,7 +20,7 @@
 #
 # "make upx" makes *compressed* versions of the 32 bit GUI and console EXEs,
 # using the excellent UPX compressor:
-#     http://upx.sourceforge.net/
+#     https://upx.github.io/
 # "make mpress" uses the MPRESS compressor for 32- and 64-bit EXEs:
 #     http://www.matcode.com/mpress.htm
 #
@@ -34,9 +34,9 @@ DEBUG=no
 OPTIMIZE=MAXSPEED
 # set to yes to make gvim, no for vim
 GUI=yes
-# set to yes if you want to use DirectWrite (DirectX)
+# set to no if you do not want to use DirectWrite (DirectX)
 # MinGW-w64 is needed, and ARCH should be set to i686 or x86-64.
-DIRECTX=no
+DIRECTX=yes
 # FEATURES=[TINY | SMALL | NORMAL | BIG | HUGE]
 # Set to TINY to make minimal version (few features).
 FEATURES=HUGE

src/Make_mvc.mak

@@ -26,7 +26,7 @@
 #	GUI interface: GUI=yes (default is no)
 #
 #	GUI with DirectWrite (DirectX): DIRECTX=yes
-#	  (default is no, requires GUI=yes and MBYTE=yes)
+#	  (default is yes if GUI=yes, requires GUI=yes and MBYTE=yes)
 #
 #	Color emoji support: COLOR_EMOJI=yes
 #	  (default is yes if DIRECTX=yes, requires WinSDK 8.1 or later.)
@@ -180,6 +180,10 @@
 
 TARGETOS = WINNT
 
+!ifndef DIRECTX
+DIRECTX = $(GUI)
+!endif
+
 # Select one of eight object code directories, depends on GUI, OLE, DEBUG and
 # interfaces.
 # If you change something else, do "make clean" first!

src/version.c

@@ -766,6 +766,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1608,
 /**/
     1607,
 /**/