- do not list non-existing files in the threads prerequisites

Makefile.in

@@ -65,6 +65,7 @@ include/bits/uClibc_config.h: extra/config/conf .config $(top_srcdir)extra/scrip
 # XXX: FIXME: this is ugly
 MAKEFLAGS += -L
 include/config/linuxthreads/old.h include/config/linuxthreads/new.h:
+	@true
 
 # For the moment, we have to keep re-running this target
 # because the fix includes scripts rely on pre-processers

libpthread/linuxthreads.old/Makefile.in

@@ -111,8 +111,7 @@ include/bits/pthreadtypes.h: | include/bits
 
 linuxthreads_headers := include/pthread.h include/semaphore.h \
 			include/bits/pthreadtypes.h
-$(linuxthreads_headers): include/config/linuxthreads/old.h \
-	    include/config/linuxthreads/new.h
+$(linuxthreads_headers): $(wildcard $(addprefix include/config/linuxthreads/,old.h new.h))
 headers-$(UCLIBC_HAS_THREADS) += $(linuxthreads_headers)
 
 objclean-y += libpthread_clean

libpthread/linuxthreads.old_db/Makefile.in

@@ -63,8 +63,7 @@ include/thread_db.h:
 	$(do_ln) ../$(PTDIR)_db/$(@F) $(top_builddir)$@
 
 linuxthreads_db_headers := include/thread_db.h
-$(linuxthreads_db_headers): include/config/linuxthreads/old.h \
-	    include/config/linuxthreads/new.h
+$(linuxthreads_db_headers): $(wildcard $(addprefix include/config/linuxthreads/,old.h new.h))
 headers-$(PTHREADS_DEBUG_SUPPORT) += $(linuxthreads_db_headers)
 
 objclean-y += libthread_db_clean

libpthread/linuxthreads/Makefile.in

@@ -124,8 +124,7 @@ include/bits/pthreadtypes.h: | include/bits
 
 linuxthreads_headers := include/pthread.h include/semaphore.h \
 			include/bits/pthreadtypes.h
-$(linuxthreads_headers): include/config/linuxthreads/old.h \
-	    include/config/linuxthreads/new.h
+$(linuxthreads_headers): $(wildcard $(addprefix include/config/linuxthreads/,old.h new.h))
 headers-$(UCLIBC_HAS_THREADS) += $(linuxthreads_headers)
 
 objclean-y += libpthread_clean

libpthread/linuxthreads_db/Makefile.in

@@ -63,8 +63,7 @@ include/thread_db.h:
 	$(do_ln) ../$(PTDIR)_db/$(@F) $(top_builddir)$@
 
 linuxthreads_db_headers := include/thread_db.h
-$(linuxthreads_db_headers): include/config/linuxthreads/old.h \
-	    include/config/linuxthreads/new.h
+$(linuxthreads_db_headers): $(wildcard $(addprefix include/config/linuxthreads/,old.h new.h))
 headers-$(PTHREADS_DEBUG_SUPPORT) += $(linuxthreads_db_headers)
 
 objclean-y += libthread_db_clean