some mingw related tweaks to the build-environment.

gtk2_ardour/wscript

@@ -403,8 +403,6 @@ def build(bld):
         # Windows VST support mingw
             obj.source += (
                 '../libs/fst/fst.c',
-                '../libs/fst/fstinfofile.c',
-                '../libs/fst/vsti.c',
                 '../libs/fst/vstwin.c',
                 '../vst/winmain.c',
                 )

wscript

@@ -407,7 +407,7 @@ def set_compiler_flags (conf,opt):
         conf.env.append_value('CXXFLAGS', optimization_flags)
 
     if opt.backtrace:
-        if platform != 'darwin' and not is_clang:
+        if platform != 'darwin' and not is_clang and not Options.options.dist_target == 'mingw':
             linker_flags += [ '-rdynamic' ]
 
     conf.env.append_value('CFLAGS', compiler_flags)