[gtkmm/gtkmm-3-24] NMake Makefiles: Silence some warnings

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

commit 5c189cafe54a005c407cea936b0903e5717c9144
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon Apr 6 00:26:20 2020 +0800

    NMake Makefiles: Silence some warnings
    
    Enable /EHsc so that we do not receive warning C4577 for constexpr
    usage.
    
    Also disable warnings C4251 and C4275 as they relate to whether we are
    using __declspec(dllimport) for the public symbols in the glibmm
    headers, when building against glibmm 2.64.0 or later.  Since we know
    what we are indeed going to use __declspec(dllimport) as we build against
    glibmm 2.64.0 or later, we can just ignore those warnings.

 MSVC_NMake/config-msvc.mak | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/MSVC_NMake/config-msvc.mak b/MSVC_NMake/config-msvc.mak
index 7962bba6..5b730122 100644
--- a/MSVC_NMake/config-msvc.mak
+++ b/MSVC_NMake/config-msvc.mak
@@ -122,9 +122,10 @@ GTKMM_DEMO_DEP_LIBS = $(GTKMM_DEP_LIBS) $(EPOXY_LIB)
 
 # CXXFLAGS
 GDKMM_BASE_CFLAGS =            \
+       /EHsc   \
        /Ivs$(PDBVER)\$(CFG)\$(PLAT)    \
        /I..\gdk /I.\gdkmm      \
-       /wd4530                 \
+       /wd4530 /wd4251 /wd4275 \
        /FImsvc_recommended_pragmas.h
 
 GTKMM_BASE_CFLAGS =            \