Fix arm-linux compile

src/linuxlike/linux.rs

@@ -158,6 +158,7 @@ pub const O_SYNC: ::c_int = 1052672;
 pub const O_RSYNC: ::c_int = 1052672;
 pub const O_DSYNC: ::c_int = 4096;
 
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 pub const MAP_32BIT: ::c_int = 0x0040;
 
 pub const TCP_MD5SIG: ::c_int = 14;