nuclide launch script: if NUCLIDE_GDB is set, run a debug session with gdb

nuclide

@@ -5,7 +5,11 @@ SRCPATH="$( cd "$( dirname $(readlink -nf $0) )" && pwd )"
 cd "$SRCPATH/bin"
 
 if [ -f "$SRCPATH"/bin/fteqw ]; then
-	./fteqw -basedir ../ $*
+	if [[ -z "${NUCLIDE_GDB}" ]]; then
+		./fteqw -basedir ../ $*
+	else
+		gdb --args ./fteqw -basedir ../ $*
+	fi
 else
 	printf "Engine is not present, please run build_engine.sh\n"
 fi