Issue #17173: Remove uses of locale-dependent C functions (isalpha() etc.) in the interpreter.

I've left a couple of them in: zlib (third-party lib), getaddrinfo.c
(doesn't include Python.h, and probably obsolete), _sre.c (legitimate
use for the re.LOCALE flag).
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 9ca7b65..e2a4ef9 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -1887,7 +1887,7 @@
                         "int() arg 2 must be >= 2 and <= 36");
         return NULL;
     }
-    while (*str != '\0' && isspace(Py_CHARMASK(*str)))
+    while (*str != '\0' && Py_ISSPACE(Py_CHARMASK(*str)))
         str++;
     if (*str == '+')
         ++str;
@@ -2131,7 +2131,7 @@
         goto onError;
     if (sign < 0)
         Py_SIZE(z) = -(Py_SIZE(z));
-    while (*str && isspace(Py_CHARMASK(*str)))
+    while (*str && Py_ISSPACE(Py_CHARMASK(*str)))
         str++;
     if (*str != '\0')
         goto onError;