Support for iOS compilation

config.sub

@@ -1400,6 +1400,8 @@ case $os in
 	-mac*)
 		os=`echo $os | sed -e 's|mac|macos|'`
 		;;
+	-ios*)
+		;;
 	-linux-dietlibc)
 		os=-linux-dietlibc
 		;;

configure.ac

@@ -264,7 +264,7 @@ dnl definitions need to be seen before any headers are included, which is a pain
 dnl to make happen otherwise.
 default_munmap="1"
 case "${host}" in
-  *-*-darwin*)
+  *-*-darwin* | *-*-ios*)
 	CFLAGS="$CFLAGS"
 	abi="macho"
 	AC_DEFINE([JEMALLOC_PURGE_MADVISE_FREE], [ ])