Create symlink so the build can handle versioned binaries

Index: Makefile.in
--- Makefile.in.orig
+++ Makefile.in
@@ -603,6 +603,7 @@ $(BOOTSTRAP_ROOT)/bootstrap/bin/erl: $(ERL_TOP)/erts/e
 	        $(ERL_TOP)/erts/etc/unix/erl.src.src > \
 			$(BOOTSTRAP_ROOT)/bootstrap/bin/erl
 	@chmod 755 $(BOOTSTRAP_ROOT)/bootstrap/bin/erl
+	@(cd $(BOOTSTRAP_ROOT)/bootstrap/bin && $(LN_S) ./erl erl${MAJ_V})
 
 $(BOOTSTRAP_ROOT)/bootstrap/bin/erlc: $(ERL_TOP)/bin/$(TARGET)/erlc $(BOOTSTRAP_ROOT)/bootstrap/target
 	@rm -f $(BOOTSTRAP_ROOT)/bootstrap/bin/erlc