Use stdlib's malloc and realloc instead of extern to avoid conflict
Reference: https://src.fedoraproject.org/rpms/ghc9.12/blob/12ecf74c5a603b552da365829135e5b62e252db1/f/hp2ps-C-gnu17.patch
===================================================================
--- ghc-9.2.8.orig/utils/hp2ps/Utilities.c
+++ ghc-9.2.8/utils/hp2ps/Utilities.c
@@ -1,10 +1,9 @@
 #include "Main.h"
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 #include "Error.h"
 
-extern void* malloc();
-
 char*
 Basename(char *name)
 {
@@ -89,7 +88,6 @@ void *
 xrealloc(void *p, size_t n)
 {
     void *r;
-    extern void *realloc();
 
     r = realloc(p, n);
     if (!r) {