In the Unix version, arrange for sigcheck() to be called via
Py_AddPendingCall().  This avoids having to call sigcheck() in the
ticker code in ceval.c's main interpreter loop.
diff --git a/Parser/intrcheck.c b/Parser/intrcheck.c
index 5213573..92fab1c 100644
--- a/Parser/intrcheck.c
+++ b/Parser/intrcheck.c
@@ -137,6 +137,8 @@
 	interrupted = 1;
 }
 
+extern int sigcheck();
+
 /* ARGSUSED */
 static RETSIGTYPE
 #ifdef _M_IX86
@@ -161,6 +163,7 @@
 		break;
 	}
 	signal(SIGINT, intcatcher);
+	Py_AddPendingCall(sigcheck, NULL);
 }
 
 void