BaseTools: Declare $(DEBUG_DIR)/<module>.efi output

$(DEBUG_DIR)/<M>.efi is generated by the recipe of
$(OUTPUT_DIR)/<M>.efi: the .efi file is generated and then copied into
$(DEBUG_DIR). At the moment the generate GNUmakefile does not declare
the dependency between these two files, which can be a problem because
$(FFS_OUTPUT_DIR)/<M>.offset depends on $(DEBUG_DIR)/<M>.efi.

Normally $(DEBUG_DIR)/<M>.efi is generated first and there is no
problem, but when an external tool builds edk2 from a Makefile, like
OP-TEE build does for instance, the parallel '-j' flag passed to Make is
inherited by the edk2 GNUmakefile from the environment. As a result Make
might try to build the $(FFS_OUTPUT_DIR)/<M>.offset target in parallel
and fail to find the .efi file:

make[1]: *** No rule to make target 'Build/ArmVirtQemu-AARCH64/DEBUG_GCC5/AARCH64/NetworkPkg/VlanConfigDxe/VlanConfigDxe/DEBUG/VlanConfigDxe.efi', needed by 'Build/ArmVirtQemu-AARCH64/DEBUG_GCC5/FV/Ffs/E4F61863-FE2C-4b56-A8F4-08519BC439DFVlanConfigDxe/VlanConfigDxe.offset'.  Stop.

If we declare the $(DEBUG_DIR) file as output of this rule, then the
generated GNUmakefile will contain the right dependency declaration:

	$(DEBUG_DIR)/VlanConfigDxe.efi: $(OUTPUT_DIR)/VlanConfigDxe.efi

and the parallel build will succeed.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

BaseTools/Conf/build_rule.template

@@ -376,6 +376,7 @@
     <OutputFile>
         $(OUTPUT_DIR)(+)$(MODULE_NAME).efi
         $(OUTPUT_DIR)(+)$(MODULE_NAME).map
+        $(DEBUG_DIR)(+)$(MODULE_NAME).efi
 
     <Command.MSFT, Command.INTEL, Command.CLANGPDB>
         "$(GENFW)" -e $(MODULE_TYPE) -o ${dst} ${src} $(GENFW_FLAGS)