try to set a good graalpython home also when we're in a binary import

Author: timfel

mx.graalpython/mx_graalpython.py

@@ -575,7 +575,10 @@ def python_checkcopyrights(args):
 #
 # ----------------------------------------------------------------------------------------------------------------------
 if not os.getenv("GRAAL_PYTHONHOME"):
-    os.environ["GRAAL_PYTHONHOME"] = os.path.join(_suite.dir, "graalpython")
+    home = os.path.join(_suite.dir, "graalpython")
+    if not os.path.exists(home):
+        home = [d for d in _suite.dists if d.name == "GRAALPYTHON_GRAALVM_SUPPORT"][0].output
+    os.environ["GRAAL_PYTHONHOME"] = home
 
 
 # ----------------------------------------------------------------------------------------------------------------------