Consider a.out files when cleaning

Author: sam-falvo

cores/IPA/Makefile

@@ -8,7 +8,7 @@ ipa.waves:
 	iverilog -s ipa_tb ../common/*.v bench/verilog/*.v rtl/verilog/*.v -I../common && vvp -n a.out && gtkwave ipa.vcd
 
 clean:
-	rm -f *.blif *.asc *.bin *.vcd
+	rm -f *.blif *.asc *.bin *.vcd a.out
 
 .PHONY: clean ipa.waves