Add target to only build tests (not run them)

Not sending upstream as this is only a start of a solution to
installable tests: It's useful for us already as is.

Upstream-Status: Inappropriate [not a complete solution]

Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
Refactored for 3.4
Signed-off-by: Armin Kuster <akuster@mvista.com>

Index: nettle-3.4/Makefile.in
===================================================================
--- nettle-3.4.orig/Makefile.in
+++ nettle-3.4/Makefile.in
@@ -55,6 +55,9 @@ clean distclean mostlyclean maintainer-c
 	  echo "Making $@ in $$d" ; (cd $$d && $(MAKE) $@); done
 	$(MAKE) $@-here
 
+buildtest:
+	echo "Making $@ in testsuite" ; (cd testsuite && $(MAKE) $@)
+
 check-here:
 	true
 
Index: nettle-3.4/testsuite/Makefile.in
===================================================================
--- nettle-3.4.orig/testsuite/Makefile.in
+++ nettle-3.4/testsuite/Makefile.in
@@ -131,6 +131,8 @@ $(TARGETS) $(EXTRA_TARGETS): testutils.$
 # data.
 VALGRIND = valgrind --error-exitcode=1 --leak-check=full --show-reachable=yes @IF_ASM@ --partial-loads-ok=yes
 
+buildtest: $(TS_ALL)
+
 # The PATH update is for windows dlls, DYLD_LIBRARY_PATH is for OSX.
 check: $(TS_ALL)
 	LD_LIBRARY_PATH=../.lib PATH="../.lib:$$PATH" DYLD_LIBRARY_PATH=../.lib \