patch 8.1.0941: macros for MS-Windows are inconsistent
Problem: Macros for MS-Windows are inconsistent, using "32", "3264 and
others.
Solution: Use MSWIN for all MS-Windows builds. Use FEAT_GUI_MSWIN for the
GUI build. (Hirohito Higashi, closes #3932)
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index c81fbd2..391277f 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -791,8 +791,8 @@
!if "$(GUI)" == "yes"
SUBSYSTEM = windows
-CFLAGS = $(CFLAGS) -DFEAT_GUI_W32
-RCFLAGS = $(RCFLAGS) -DFEAT_GUI_W32
+CFLAGS = $(CFLAGS) -DFEAT_GUI
+RCFLAGS = $(RCFLAGS) -DFEAT_GUI
VIM = g$(VIM)
GUI_INCL = \
gui.h