bpo-30022: Get rid of using EnvironmentError and IOError (except test… (#1051)

diff --git a/Modules/readline.c b/Modules/readline.c
index 389954f..dfbbb29 100644
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -188,7 +188,7 @@
     } else
         errno = rl_read_init_file(NULL);
     if (errno)
-        return PyErr_SetFromErrno(PyExc_IOError);
+        return PyErr_SetFromErrno(PyExc_OSError);
     Py_RETURN_NONE;
 }
 
@@ -214,7 +214,7 @@
     } else
         errno = read_history(NULL);
     if (errno)
-        return PyErr_SetFromErrno(PyExc_IOError);
+        return PyErr_SetFromErrno(PyExc_OSError);
     Py_RETURN_NONE;
 }
 
@@ -249,7 +249,7 @@
     Py_XDECREF(filename_bytes);
     errno = err;
     if (errno)
-        return PyErr_SetFromErrno(PyExc_IOError);
+        return PyErr_SetFromErrno(PyExc_OSError);
     Py_RETURN_NONE;
 }
 
@@ -285,7 +285,7 @@
     Py_XDECREF(filename_bytes);
     errno = err;
     if (errno)
-        return PyErr_SetFromErrno(PyExc_IOError);
+        return PyErr_SetFromErrno(PyExc_OSError);
     Py_RETURN_NONE;
 }