Ensure dump-words-to-file creates the target

Even if word list is empty.

Not creating the file was causing print of error messages that were
not preventing compilation to continue when compiling Java module with
no source.

Change-Id: I095b85f85ed6fcef5882afa39d4af51b78124c7c

core/definitions.mk

@@ -1710,6 +1710,7 @@ endef
 # dump-words-to-file, <word list>, <output file>
 define dump-words-to-file
         @rm -f $(2)
+        @touch $(2)
         @$(call emit-line,$(wordlist 1,200,$(1)),$(2))
         @$(call emit-line,$(wordlist 201,400,$(1)),$(2))
         @$(call emit-line,$(wordlist 401,600,$(1)),$(2))