fix makefile forgood with an ugly hack

Makefile

 CLEAN_HOME?=/opt/clean
+GCCVERSIONGTEQ6:=$(shell expr `gcc -dumpversion | cut -f1 -d.` \>= 6)
+
 test: test.icl TTY.icl TTY.dcl Clean\ System\ Files/ctty.o
-	if hash gcc-5 2>/dev/null;\
-	then clm -dynamics -l -no-pie -I $(CLEAN_HOME)/lib/Dynamics $(basename $<) -o $@; \
-	else clm -dynamics -I $(CLEAN_HOME)/lib/Dynamics $(basename $<) -o $@; \
-	fi
+ifeq "$(GCCVERSIONGTEQ6)" "1"
+	clm -l -no-pie -I $(CLEAN_HOME)/lib/Dynamics $(basename $<) -o $@
+else
+	clm -I $(CLEAN_HOME)/lib/Dynamics $(basename $<) -o $@
+endif
 	
 
 Clean\ System\ Files/ctty.o: tty.c
-	if hash gcc-5 2>/dev/null;\
-	then gcc-5 -DDEBUG -c $< -o "$@"; \
-	else gcc -DDEBUG -c $< -o "$@"; \
-	fi
+ifeq "$(GCCVERSIONGTEQ6)" "1"
+		gcc-5 -DDEBUG -c $< -o "$@"
+else
+		gcc -DDEBUG -c $< -o "$@"
+endif
 
 clean:
 	$(RM) -r Clean\ System\ Files/* test