depend-cleanup.sh: Handle rs(1) moving to C++.

To support changes in filenames for programs (and not just libraries),
update clean_dep() to check .depend.foo.o files as well as
.depend.foo.pico files.

tools/build/depend-cleanup.sh

@@ -37,6 +37,15 @@ clean_dep()
 		    "$OBJTOP"/obj-lib32/$1/.depend.$2.* \
 		    "$OBJTOP"/obj-lib32/$1/$2.*o
 	fi
+	if [ -e "$OBJTOP"/$1/.depend.$2.o ] && \
+	    egrep -qw "$2\.$3" "$OBJTOP"/$1/.depend.$2.o; then \
+		echo "Removing stale dependencies and objects for $2.$3"; \
+		rm -f \
+		    "$OBJTOP"/$1/.depend.$2.* \
+		    "$OBJTOP"/$1/$2.*o \
+		    "$OBJTOP"/obj-lib32/$1/.depend.$2.* \
+		    "$OBJTOP"/obj-lib32/$1/$2.*o
+	fi
 }
 
 # Date      Rev      Description
@@ -98,3 +107,6 @@ if stat "$OBJTOP"/tests/sys/kqueue/libkqueue/*kqtest* \
 	rm -f "$OBJTOP"/tests/sys/kqueue/libkqueue/.depend.* \
 	   "$OBJTOP"/tests/sys/kqueue/libkqueue/*
 fi
+
+# 20221115  42d10b1b56f2    move from rs.c to rs.cc
+clean_dep   usr.bin/rs      rs c