osutil: replace #import with #include, and add a check for it

contrib/check-code.py

@@ -180,6 +180,7 cpats = [
     (r'^[^#]\w[+/*]\w', "missing whitespace in expression"),
     (r'^#\s+\w', "use #foo, not # foo"),
     (r'[^\n]\Z', "no trailing newline"),
+    (r'^\s*#import\b', "use only #include in standard C code"),
 ]
 
 cfilters = [

mercurial/osutil.c

@@ -515,7 +515,7 bail:
 #endif
 
 #ifdef __APPLE__
-#import <ApplicationServices/ApplicationServices.h>
+#include <ApplicationServices/ApplicationServices.h>
 
 static PyObject *isgui(PyObject *self)
 {