Some more cross tweaking.

cross/ubuntu-mingw.txt

@@ -1,7 +1,7 @@
 name = 'windows'
 exe_wrapper = 'wine' # A command used to run generated executables.
 c = '/usr/bin/i686-w64-mingw32-gcc'
-cpp = '/usr/bin/i686-w64-mingw32-gcc'
+cpp = '/usr/bin/i686-w64-mingw32-g++'
 ar = '/usr/bin/i686-w64-mingw32-ar'
 strip = '/usr/bin/i686-w64-mingw32-strip'
 

meson_test.py

@@ -70,7 +70,7 @@ def run_single_test(wrap, test):
     global tests_failed
     if test.fname[0].endswith('.jar'):
         cmd = ['java', '-jar'] + test.fname
-    elif run_with_mono(test.fname[0]):
+    elif not test.is_cross and run_with_mono(test.fname[0]):
         cmd = ['mono'] + test.fname
     else:
         if test.is_cross: