Include relevant system headers before defining fallbacks

Otherwise we may define the fallbacks, and later inclusion of the
system headers may attempt to redefine those.

Fixes GH-17112.
Closes GH-17129.

NEWS

@@ -32,6 +32,7 @@ PHP                                                                        NEWS
 - FPM:
   . Fixed bug GH-13437 (FPM: ERROR: scoreboard: failed to lock (already
     locked)). (Jakub Zelenka)
+  . Fixed bug GH-17112 (Macro redefinitions). (cmb, nielsdos)
 
 - GD:
   . Fixed bug GH-16255 (Unexpected nan value in ext/gd/libgd/gd_filter.c).
@@ -44,6 +45,9 @@ PHP                                                                        NEWS
 - Iconv:
   . Fixed bug GH-17047 (UAF on iconv filter failure). (nielsdos)
 
+- MBString:
+  . Fixed bug GH-17112 (Macro redefinitions). (nielsdos, cmb)
+
 - Opcache:
   . opcache_get_configuration() properly reports jit_prof_threshold. (cmb)
 

sapi/fpm/fpm/fpm_config.h

@@ -2,6 +2,16 @@
 
 #include <php_config.h>
 
+#ifdef HAVE_ARPA_INET_H
+# include <arpa/inet.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+
 /* Solaris does not have it */
 #ifndef INADDR_NONE
 # define INADDR_NONE (-1)