put each built artifact in its own dir

Author: bradjc

Makefile

@@ -205,8 +205,8 @@ $(call assign-vars, elf12, F=0x10020000 R=0x20004000 T=thumbv6m-none-eabi A=cort
 $(call assign-vars, elf13, F=0x10028000 R=0x2000c000 T=thumbv6m-none-eabi A=cortex-m0)
 
 elf01 elf02 elf03 elf04 elf05 elf06 elf07 elf08 elf09 elf10 elf11 elf12 elf13:
-	LINKER_FLASH=$(F) LINKER_RAM=$(R) cargo build --example $(EXAMPLE) $(features) --target=$(T) $(release)
-	cp target/$(T)/release/examples/$(EXAMPLE) target/$(EXAMPLE)/$(A).$(F).$(R).elf
+	LINKER_FLASH=$(F) LINKER_RAM=$(R) cargo build --example $(EXAMPLE) $(features) --target=$(T) $(release) --out-dir target/$(A).$(F).$(R) -Z unstable-options
+	cp target/$(A).$(F).$(R)/$(T)/release/examples/$(EXAMPLE) target/$(EXAMPLE)/$(A).$(F).$(R).elf
 	$(eval ELF_LIST += target/$(EXAMPLE)/$(A).$(F).$(R).elf)
 
 elfs: elf01 elf02 elf03 elf04 elf05 elf06 elf07 elf08 elf09 elf10 elf11 elf12 elf13