stressapptest: Fix build with libc++

when using libc++ instead of libstdc++, __gnu_cxx namespace
is not available

Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-benchmark/stressapptest/stressapptest/libcplusplus-compat.patch

@@ -0,0 +1,28 @@
+Fix compile on sytems using libc++ instead of libstdc++
+
+libc++ does not really implement __gnu_cxx namespace and it
+compiles fine without this namespace, therefore detect libc++
+and if it is used them exclude this namespace 
+
+See https://github.com/stressapptest/stressapptest/issues/47
+
+Fixes
+
+./sattypes.h:33:17: error: expected namespace name
+using namespace __gnu_cxx; //NOLINT
+
+Upstream-Status: Pending
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+
+--- stressapptest-1.0.9.orig/src/sattypes.h
++++ stressapptest-1.0.9/src/sattypes.h
+@@ -30,7 +30,9 @@
+ #include "stressapptest_config_android.h"  // NOLINT
+ #else
+ #include "stressapptest_config.h"  // NOLINT
++#ifndef _LIBCPP_VERSION
+ using namespace __gnu_cxx;  //NOLINT
++#endif  // _LIBCPP_VERSION
+ #endif  // __ANDROID__
+ using namespace std;
+

meta-oe/recipes-benchmark/stressapptest/stressapptest_1.0.9.bb

@@ -9,7 +9,9 @@ SECTION = "benchmark"
 LICENSE = "Apache-2.0"
 LIC_FILES_CHKSUM = "file://COPYING;md5=55ea9d559f985fb4834317d8ed6b9e58"
 
-SRC_URI = "https://github.com/${PN}/${PN}/archive/v${PV}.tar.gz"
+SRC_URI = "https://github.com/${PN}/${PN}/archive/v${PV}.tar.gz \
+           file://libcplusplus-compat.patch \
+          "
 
 SRC_URI[md5sum] = "d3a526c174c049dd7a1068dc74a62be2"
 SRC_URI[sha256sum] = "2ba470587ad4f6ae92057d427c3a2a2756e5f10bd25cd91e62eaef55a40b30a1"