[pangomm] NMake Makefiles: Ignore warnings C4251 and C4275

[Chun-wei Fan <fanchunwei src gnome org>]

commit aff0878a84fa05aaa0afb9ca37697269e3bc7b43
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Thu Mar 12 15:16:23 2020 +0800

    NMake Makefiles: Ignore warnings C4251 and C4275
    
    We might well be building against glibmm that is not built using gendef,
    so we get C4251 and C4275 warnings when building against such GLib
    builds.  Ignore those warnings, since we know quite well that we are
    importing from glibmm's import libraries using __declspec(dllimport) in
    this case.

 MSVC_NMake/config-msvc.mak | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/MSVC_NMake/config-msvc.mak b/MSVC_NMake/config-msvc.mak
index 2356cad..830c4f3 100644
--- a/MSVC_NMake/config-msvc.mak
+++ b/MSVC_NMake/config-msvc.mak
@@ -32,7 +32,7 @@ PANGOMM_BASE_CFLAGS =                 \
        /Ivs$(VSVER)\$(CFG)\$(PLAT)     \
        /I..\untracked\pango /I..\untracked\pango\pangomm               \
        /I..\pango /I..\pango\pangomm /I.\pangomm               \
-       /wd4530 /std:c++17      \
+       /wd4530 /wd4251 /wd4275 /std:c++17      \
        /FImsvc_recommended_pragmas.h
 
 PANGOMM_EXTRA_INCLUDES =       \