patch 9.0.0496: no good reason to keep supporting Windows-XP

Problem:    No good reason to keep supporting Windows-XP.
Solution:   Drop Windows-XP support. (Ken Takata, closes #11089)
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index 7619fdb..415bb5c 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -1,7 +1,7 @@
-# Makefile for Vim on Win32 (Windows XP/2003/Vista/7/8/10) and Win64,
-# using the Microsoft Visual C++ compilers. Known to work with VC10 (VS2010),
-# VC11 (VS2012), VC12 (VS2013), VC14 (VS2015), VC14.1 (VS2017) and
-# VC14.2 (VS2019).
+# Makefile for Vim on Win32 (Windows 7/8/10/11) and Win64, using the Microsoft
+# Visual C++ compilers. Known to work with VC10 (VS2010), VC11 (VS2012), VC12
+# (VS2013), VC14 (VS2015), VC14.1 (VS2017), VC14.2 (VS2019) and VC14.3
+# (VS2022).
 #
 # To build using other Windows compilers, see INSTALLpc.txt
 #
@@ -128,13 +128,13 @@
 #
 #	Optimization: OPTIMIZE=[SPACE, SPEED, MAXSPEED] (default is MAXSPEED)
 #
-#	Processor Version: CPUNR=[any, i586, i686, sse, sse2, avx, avx2] (default is
-#	any)
+#	Processor Version: CPUNR=[any, i686, sse, sse2, avx, avx2] (default is
+#	sse2)
 #	  avx is available on Visual C++ 2010 and after.
 #	  avx2 is available on Visual C++ 2013 Update 2 and after.
 #
-#	Version Support: WINVER=[0x0501, 0x0502, 0x0600, 0x0601, 0x0602,
-#	0x0603, 0x0A00] (default is 0x0501)
+#	Version Support: WINVER=[0x0601, 0x0602, 0x0603, 0x0A00] (default is
+#	0x0601)
 #	Supported versions depends on your target SDK, check SDKDDKVer.h
 #	See https://docs.microsoft.com/en-us/cpp/porting/modifying-winver-and-win32-winnt
 #
@@ -303,9 +303,9 @@
 MSVCRT_NAME = vcruntime$(MSVCRT_VER)
 !endif
 
-### Set the default $(WINVER) to make it work with VC++7.0 (VS.NET)
+### Set the default $(WINVER) to make it work with Windows 7
 !ifndef WINVER
-WINVER = 0x0501
+WINVER = 0x0601
 !endif
 
 # Use multiprocess build
@@ -523,27 +523,27 @@
 
 ### Validate CPUNR
 !ifndef CPUNR
-# default to untargeted code
-CPUNR = any
-!elseif "$(CPUNR)" == "i386" || "$(CPUNR)" == "i486"
-# alias i386 and i486 to i586
+# default to SSE2
+CPUNR = sse2
+!elseif "$(CPUNR)" == "i386" || "$(CPUNR)" == "i486" || "$(CPUNR)" == "i586"
+# alias i386, i486 and i586 to i686
 ! message *** WARNING CPUNR=$(CPUNR) is not a valid target architecture.
-! message Windows XP is the minimum target OS, with a minimum target
-! message architecture of i586.
-! message Retargeting to i586
-CPUNR = i586
+! message Windows 7 is the minimum target OS, with a minimum target
+! message architecture of i686.
+! message Retargeting to i686
+CPUNR = i686
 !elseif "$(CPUNR)" == "pentium4"
 # alias pentium4 to sse2
 ! message *** WARNING CPUNR=pentium4 is deprecated in favour of sse2.
 ! message Retargeting to sse2.
 CPUNR = sse2
-!elseif "$(CPUNR)" != "any" && "$(CPUNR)" != "i586" && "$(CPUNR)" != "i686" && "$(CPUNR)" != "sse" && "$(CPUNR)" != "sse2" && "$(CPUNR)" != "avx" && "$(CPUNR)" != "avx2"
+!elseif "$(CPUNR)" != "any" && "$(CPUNR)" != "i686" && "$(CPUNR)" != "sse" && "$(CPUNR)" != "sse2" && "$(CPUNR)" != "avx" && "$(CPUNR)" != "avx2"
 ! error *** ERROR Unknown target architecture "$(CPUNR)". Make aborted.
 !endif
 
 # Convert processor ID to MVC-compatible number
 # IA32/SSE/SSE2 are only supported on x86
-!if "$(ASSEMBLY_ARCHITECTURE)" == "i386" && ("$(CPUNR)" == "i586" || "$(CPUNR)" == "i686" || "$(CPUNR)" == "any")
+!if "$(ASSEMBLY_ARCHITECTURE)" == "i386" && ("$(CPUNR)" == "i686" || "$(CPUNR)" == "any")
 # VC<11 generates fp87 code by default
 ! if $(MSVC_MAJOR) < 11
 CPUARG =
@@ -1684,7 +1684,7 @@
 	$(CC) $(CFLAGS_OUTDIR) $(TCL_INC) if_tcl.c
 
 $(OUTDIR)/iscygpty.obj:	$(OUTDIR) iscygpty.c $(CUI_INCL)
-	$(CC) $(CFLAGS_OUTDIR) iscygpty.c -D_WIN32_WINNT=0x0600 -DUSE_DYNFILEID -DENABLE_STUB_IMPL
+	$(CC) $(CFLAGS_OUTDIR) iscygpty.c
 
 $(OUTDIR)/job.obj:	$(OUTDIR) job.c $(INCL)