Disable import check when cross-compiling

Once Python has compiled an extension (i.e some C code, potentially
linked to a library), it tries to import it. This cannot work in
cross-compilation mode, so we just disable this check.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 setup.py |    4 ++++
 1 file changed, 4 insertions(+)

Index: Python-2.7.2/setup.py
===================================================================
--- Python-2.7.2.orig/setup.py
+++ Python-2.7.2/setup.py
@@ -304,6 +304,10 @@
             self.announce('WARNING: skipping import check for Cygwin-based "%s"'
                 % ext.name)
             return
+        if os.environ.get('CROSS_COMPILING') == 'yes':
+            self.announce('WARNING: skipping import check for cross compiled "%s"'
+                          % ext.name)
+            return
         ext_filename = os.path.join(
             self.build_lib,
             self.get_ext_filename(self.get_ext_fullname(ext.name)))