[atkmm/atkmm-2-28] NMake Makefiles: Use /utf-8 for MSVC 2015 and later

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

commit 22aece393b974e2d1ab9f383aaead2c4850902d6
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Fri Feb 7 18:33:25 2020 +0800

    NMake Makefiles: Use /utf-8 for MSVC 2015 and later
    
    This will prevent error C4819 due to unicode handling issues in the
    compiler, which can be raised when building on an East-Asian locale
    (Chinese, Japanese and Korean).  This build flag, however, is provided
    only in Visual Studio 2015 and later, so 2013 users cannot benefit from
    this change.

 MSVC_NMake/config-msvc.mak | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/MSVC_NMake/config-msvc.mak b/MSVC_NMake/config-msvc.mak
index a8b05fc..9a019ef 100644
--- a/MSVC_NMake/config-msvc.mak
+++ b/MSVC_NMake/config-msvc.mak
@@ -27,6 +27,10 @@ ATKMM_BASE_CFLAGS =                  \
        /wd4530 /EHsc   \
        /FImsvc_recommended_pragmas.h
 
+!if $(PDBVER) > 12
+ATKMM_BASE_CFLAGS = $(ATKMM_BASE_CFLAGS) /utf-8
+!endif
+
 ATKMM_EXTRA_INCLUDES = \
        /I$(PREFIX)\include\atk-$(ATK_API_VERSION)      \
        /I$(PREFIX)\include\glibmm-$(GLIBMM_MAJOR_VERSION).$(GLIBMM_MINOR_VERSION)      \