Made test Makefiles work with CMD.EXE

test/val/Makefile

@@ -5,18 +5,18 @@ ifneq ($(shell echo),)
   CMD_EXE := 1
 endif
 
+ifdef CMD_EXE
+  RM = del /f $(subst /,\,$1)
+else
+  RM = $(RM) $1
+endif
+
 CC65FLAGS := -t sim6502
 SIM65FLAGS := -x 200000000
 
 CL65 := $(if $(wildcard ../../bin/cl65*),../../bin/cl65,cl65)
 SIM65 := $(if $(wildcard ../../bin/sim65*),../../bin/sim65,sim65)
 
-ifdef CMD_EXE
-RM := del /f
-else
-RM := rm -f
-endif
-
 WORKDIR := ../../testwrk
 
 .PHONY: all clean
@@ -66,5 +66,5 @@ $(WORKDIR)/%.or.prg: %.c
 	$(SIM65) $(SIM65FLAGS) $@
 
 clean:
-	@$(RM) $(TESTS)
-	@$(RM) $(SOURCES:.c=.o)
+	-@$(call RM,$(TESTS))
+	-@$(call RM,$(SOURCES:.c=.o))