Removed string0.c and added -lc to link micromusl c lib

Note: string0.c has not been deleted, it just was removed from
the Makefile.  Also -lc was added after all the object files
so gcc should only cherry-pick the c library functions that
are actually needed.

stm/Makefile

@@ -17,7 +17,6 @@ SRC_C = \
 	printf.c \
 	system_stm32f4xx.c \
 	stm32fxxx_it.c \
-	string0.c \
 	malloc0.c \
 	systick.c  \
 	lexerstm.c \
@@ -147,7 +146,7 @@ $(BUILD)/flash1.bin: $(BUILD)/flash.elf
 	arm-none-eabi-objcopy -O binary -j .text -j .data $^ $@
 
 $(BUILD)/flash.elf: $(OBJ)
-	$(LD) $(LDFLAGS) -o $@ $(OBJ)
+	$(LD) $(LDFLAGS) -o $@ $(OBJ) -L../micromusl/build/lib -lc
 	arm-none-eabi-size $@
 
 $(BUILD):