[C++ PATCH] Pass RUNTESTFLAGS through from check-c++1z

[Jakub Jelinek]

Hi!

I've been surprised that
make check-c++1z RUNTESTFLAGS=dg.exp=direct-enum*
attempts to run the whole testsuite in -std=c++1z mode,
while if I replace check-c++1z with check-g++ or check-c++-all,
it works properly.

The following patch passes the var down to the submake, so that it works
as expected.  Ok for trunk?

2016-09-23  Jakub Jelinek  <jakub@redhat.com>

	* Make-lang.in (check-c++1z): Pass RUNTESTFLAGS down to
	make check-g++.

--- gcc/cp/Make-lang.in.jj	2016-06-28 14:13:37.000000000 +0200
+++ gcc/cp/Make-lang.in	2016-09-23 19:16:54.382005180 +0200
@@ -164,7 +164,7 @@ check-c++ : check-g++
 
 # Run the testsuite in C++1z mode.
 check-c++1z:
-	$(MAKE) GXX_TESTSUITE_STDS=1z check-g++
+	$(MAKE) RUNTESTFLAGS="$(RUNTESTFLAGS)" GXX_TESTSUITE_STDS=1z check-g++
 
 # Run the testsuite in all standard conformance levels.
 check-c++-all:

	Jakub