CDRIVER-1421 zSeries unused function error

Author: bjori

.evergreen/compile-unix.sh

@@ -122,6 +122,9 @@ case "$MARCH" in
          CFLAGS="$CFLAGS -Werror"
       fi
    ;;
+   s390x)
+      CFLAGS="$CFLAGS -march=z196 -mtune=zEC12"
+   ;;
    x86_64)
       CFLAGS="$CFLAGS -m64 -march=x86-64"
       if [ "$CC" = "gcc" ]; then

src/mongoc/mongoc-rpc.c

@@ -165,7 +165,7 @@
 #include "op-msg.def"
 #include "op-query.def"
 #include "op-reply.def"
-#include "op-reply-header.def"
+/* Don't process generate _mongoc_rpc_swab_to_le_reply_header from op-reply-header.def */
 #include "op-update.def"
 
 #undef RPC
@@ -195,12 +195,9 @@
 #include "op-msg.def"
 #include "op-query.def"
 #include "op-reply.def"
+/* Don't process generate _mongoc_rpc_swab_from_le_reply_header from op-reply-header.def */
 #include "op-update.def"
 
-/* don't process op-reply-header.def, don't need to generate
-   _mongoc_rpc_swab_to_le_head_only / _mongoc_rpc_swab_from_le_head_only
-*/
-
 #undef RPC
 #undef ENUM_FIELD
 #undef INT32_FIELD