fix repeated expression evaluation in f-string implementation for !s/r/a...

fix repeated expression evaluation in f-string implementation for !s/r/a conversions by switching from macro to inline function

Cython/Utility/StringTools.c

@@ -835,12 +835,20 @@ static CYTHON_INLINE int __Pyx_PyByteArray_Append(PyObject* bytearray, int value
 
 //////////////////// PyObjectFormatAndDecref.proto ////////////////////
 
-#define __Pyx_PyObject_FormatSimpleAndDecref(s, f) \
-    ((unlikely(!s) || likely(PyUnicode_CheckExact(s))) ? s : __Pyx_PyObject_FormatAndDecref(s, f))
+static CYTHON_INLINE PyObject* __Pyx_PyObject_FormatSimpleAndDecref(PyObject* s, PyObject* f);
 static CYTHON_INLINE PyObject* __Pyx_PyObject_FormatAndDecref(PyObject* s, PyObject* f);
 
 //////////////////// PyObjectFormatAndDecref ////////////////////
 
+static CYTHON_INLINE PyObject* __Pyx_PyObject_FormatSimpleAndDecref(PyObject* s, PyObject* f) {
+    if (unlikely(!s)) return NULL;
+    if (likely(PyUnicode_CheckExact(s))) return s;
+    #if PY_MAJOR_VERSION < 3
+    if (likely(PyString_CheckExact(s))) return s;
+    #endif
+    return __Pyx_PyObject_FormatAndDecref(s, f);
+}
+
 static CYTHON_INLINE PyObject* __Pyx_PyObject_FormatAndDecref(PyObject* s, PyObject* f) {
     PyObject *result = PyObject_Format(s, f);
     Py_DECREF(s);