The DTrace generated files were missing dependency on the Makefile, so
they didn't get regenerated when ./configure was re-run. This would
create problem especially between ./configure --enable-tracing vs
./configure --disable-tracing invocations.
BUILT_SOURCES += probes.h
CLEANFILES += probes.h probes.o
-probes.h: probes.d
+probes.h: Makefile probes.d
$(AM_V_DTRACE)$(DTRACE) -s $(srcdir)/probes.d -h -o $@
-probes.lo: probes.d $(DTRACE_DEPS)
+probes.lo: Makefile probes.d $(DTRACE_DEPS)
$(AM_V_DTRACE)$(LIBTOOL) --mode=compile --tag=CC $(DTRACE) -s $(srcdir)/probes.d -G -o $@ $(DTRACE_OBJS)
if HAVE_DTRACE