Delete sigcheck.c since it appears unused (#1723)

Include/pyerrors.h

@@ -352,7 +352,7 @@ PyAPI_FUNC(PyObject *) _PyErr_TrySetFromCause(
 #endif
 
 
-/* In sigcheck.c or signalmodule.c */
+/* In signalmodule.c */
 PyAPI_FUNC(int) PyErr_CheckSignals(void);
 PyAPI_FUNC(void) PyErr_SetInterrupt(void);
 

Python/sigcheck.c

-
-/* Sigcheck is similar to intrcheck() but sets an exception when an
-   interrupt occurs.  It can't be in the intrcheck.c file since that
-   file (and the whole directory it is in) doesn't know about objects
-   or exceptions.  It can't be in errors.c because it can be
-   overridden (at link time) by a more powerful version implemented in
-   signalmodule.c. */
-
-#include "Python.h"
-
-/* ARGSUSED */
-int
-PyErr_CheckSignals(void)
-{
-	if (!PyOS_InterruptOccurred())
-		return 0;
-	PyErr_SetNone(PyExc_KeyboardInterrupt);
-	return -1;
-}