Link wxMSW with msimg32.lib now that AlphaBlend() is used statically.

Implicitly link msimg32.lib in when using MSVC and add it to MinGW (and
Borland) makefiles.

This should have been part of r77029.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77039 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/dc.cpp

@@ -51,6 +51,18 @@
 #include "wx/msw/private/dc.h"
 #include "wx/private/textmeasure.h"
 
+// In the previous versions of wxWidgets, AlphaBlend() was dynamically loaded
+// from msimg32.dll during the run-time, so we didn't need to link with this
+// library. Now that we use the function statically, we do need to link with it
+// and we do it implicitly from here for MSVC users to avoid breaking the build
+// of the existing projects which didn't link with.
+//
+// MinGW users will need to add -lmsimg32 to their make/project files
+// explicitly however as MinGW doesn't have this pragma equivalent.
+#ifdef _MSC_VER
+    #pragma comment(lib, "msimg32")
+#endif
+
 using namespace wxMSWImpl;
 
 #ifndef AC_SRC_ALPHA