patch 8.2.0594: MS-Windows: cannot build with WINVER set to 0x0501

Problem:    MS-Windows: cannot build with WINVER set to 0x0501.
Solution:   Only use inet_ntop() when available. (Ozaki Kiichi, closes #5946)
diff --git a/src/Make_cyg_ming.mak b/src/Make_cyg_ming.mak
index d767c79..750e940 100644
--- a/src/Make_cyg_ming.mak
+++ b/src/Make_cyg_ming.mak
@@ -625,6 +625,9 @@
 
 ifeq ($(CHANNEL),yes)
 DEFINES += -DFEAT_JOB_CHANNEL -DFEAT_IPV6
+ ifeq ($(shell expr "$(WINVER)" \>= 0x600),1)
+DEFINES += -DHAVE_INET_NTOP
+ endif
 endif
 
 ifeq ($(TERMINAL),yes)