Missing --tag while building C++ tests.

--- tests/Makefile.in.orig	2008-09-24 05:11:43.000000000 +0200
+++ tests/Makefile.in	2008-10-03 01:36:19.000000000 +0200
@@ -1293,11 +1293,11 @@ LINK = $(LIBTOOL) --mode=link $(CCLD) $(
 	$(AM_LDFLAGS) $(LDFLAGS) -o $@
 CXXCOMPILE = $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
 	$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS)
-LTCXXCOMPILE = $(LIBTOOL) --mode=compile $(CXX) $(DEFS) \
+LTCXXCOMPILE = $(LIBTOOL) --tag=CXX --mode=compile $(CXX) $(DEFS) \
 	$(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) \
 	$(AM_CXXFLAGS) $(CXXFLAGS)
 CXXLD = $(CXX)
-CXXLINK = $(LIBTOOL) --mode=link $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) \
+CXXLINK = $(LIBTOOL) --tag=CXX --mode=link $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) \
 	$(AM_LDFLAGS) $(LDFLAGS) -o $@
 DIST_SOURCES = $(am__autotestkeywords_SOURCES_DIST) pixbuf-lowmem.c \
 	pixbuf-random.c pixbuf-randomly-modified.c pixbuf-read.c \