patch 8.1.0084: user name completion does not work on MS-Windows

Problem:    User name completion does not work on MS-Windows.
Solution:   Use NetUserEnum() to get user names. (Yasuhiro Matsumoto)
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index 5ca5380..8cb443c 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -489,10 +489,11 @@
 
 # need advapi32.lib for GetUserName()
 # need shell32.lib for ExtractIcon()
+# need netapi32.lib for NetUserEnum()
 # gdi32.lib and comdlg32.lib for printing support
 # ole32.lib and uuid.lib are needed for FEAT_SHORTCUT
 CON_LIB = oldnames.lib kernel32.lib advapi32.lib shell32.lib gdi32.lib \
-          comdlg32.lib ole32.lib uuid.lib /machine:$(CPU)
+          comdlg32.lib ole32.lib netapi32.lib uuid.lib /machine:$(CPU)
 !if "$(DELAYLOAD)" == "yes"
 CON_LIB = $(CON_LIB) /DELAYLOAD:comdlg32.dll /DELAYLOAD:ole32.dll DelayImp.lib
 !endif
@@ -801,7 +802,7 @@
 	$(OUTDIR)\os_w32exe.obj
 GUI_LIB = \
 	gdi32.lib version.lib $(IME_LIB) \
-	winspool.lib comctl32.lib advapi32.lib shell32.lib \
+	winspool.lib comctl32.lib advapi32.lib shell32.lib netapi32.lib \
 	/machine:$(CPU)
 !else
 SUBSYSTEM = console