FLAGS_OPT_RTS doesn't honor the CFLAGS.

Index: configure
--- configure.orig
+++ configure
@@ -15371,7 +15371,7 @@ if test "$C_COMP_VISUALC" = yes; then
 
 else
 
-  BUILD_OBJ_RTS="\${C_COMPILER} \${FLAGS_OPT_RTS} \${FLAGS_OBJ} \${DEFS_OBJ} -I\"\${GAMBITDIR_INCLUDE}\" -c -o \${BUILD_OBJ_OUTPUT_FILENAME_PARAM} \${BUILD_OBJ_CC_OPTIONS_PARAM} \${BUILD_OBJ_INPUT_FILENAMES_PARAM}"
+  BUILD_OBJ_RTS="\${C_COMPILER} \${FLAGS_OPT} \${FLAGS_OBJ} \${DEFS_OBJ} -I\"\${GAMBITDIR_INCLUDE}\" -c -o \${BUILD_OBJ_OUTPUT_FILENAME_PARAM} \${BUILD_OBJ_CC_OPTIONS_PARAM} \${BUILD_OBJ_INPUT_FILENAMES_PARAM}"
 
   BUILD_OBJ="\${C_COMPILER} \${FLAGS_OPT} \${FLAGS_OBJ} \${DEFS_OBJ} -I\"\${GAMBITDIR_INCLUDE}\" -c -o \${BUILD_OBJ_OUTPUT_FILENAME_PARAM} \${BUILD_OBJ_CC_OPTIONS_PARAM} \${BUILD_OBJ_INPUT_FILENAMES_PARAM}"