wmake: Improved handling of dependencies when files are removed

wmake/rules/General/transform

@@ -30,6 +30,10 @@ $(OBJECTS_DIR)/%.dep : %
 	@$(WM_SCRIPTS)/makeTargetDir $@
 	@$(WMAKE_BIN)/wmkdep -I$(*D) $(LIB_HEADER_DIRS) $< | \
 		sed -e 's,^$(WM_PROJECT_DIR)/,$$(WM_PROJECT_DIR)/,' \
-			-e 's,^$(WM_THIRD_PARTY_DIR)/,$$(WM_THIRD_PARTY_DIR)/,' > $@
+			-e 's,^$(WM_THIRD_PARTY_DIR)/,$$(WM_THIRD_PARTY_DIR)/,' > $@.tmp; \
+		cp $@.tmp $@; \
+		sed -e 's/^[^:]*: *//' -e 's/ *\\$$//' -e '/^$$/ d' -e 's/$$/ :/' \
+            $@.tmp >> $@; \
+		rm -f $@.tmp
 
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