[3.10] GH-102711: Fix warnings found by clang (GH-102712) (#103076)

There are some warnings if build python via clang:

Parser/pegen.c:812:31: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
_PyPegen_clear_memo_statistics()
                              ^
                               void

Parser/pegen.c:820:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
_PyPegen_get_memo_statistics()
                            ^
                             void

Fix it to make clang happy.

(cherry picked from commit 7703def)

Signed-off-by: Chenxi Mao <chenxi.mao@suse.com>
Co-authored-by: Chenxi Mao <chenxi.mao@suse.com>

Misc/NEWS.d/next/Build/2023-03-15-02-03-39.gh-issue-102711.zTkjts.rst

@@ -0,0 +1 @@
+Fix ``-Wstrict-prototypes`` compiler warnings.

Parser/pegen.c

@@ -809,15 +809,15 @@ _PyPegen_fill_token(Parser *p)
 static long memo_statistics[NSTATISTICS];
 
 void
-_PyPegen_clear_memo_statistics()
+_PyPegen_clear_memo_statistics(void)
 {
     for (int i = 0; i < NSTATISTICS; i++) {
         memo_statistics[i] = 0;
     }
 }
 
 PyObject *
-_PyPegen_get_memo_statistics()
+_PyPegen_get_memo_statistics(void)
 {
     PyObject *ret = PyList_New(NSTATISTICS);
     if (ret == NULL) {