Add libstdc++ as a dependency for build-target-art-golem.

Needed for running with ART_TARGET_LINUX=true

Test: builds and runs.
Change-Id: Idf74eff0a4114952b71781ed80de5bbe75f666ae
diff --git a/Android.mk b/Android.mk
index b2716cd..cf3a9e7 100644
--- a/Android.mk
+++ b/Android.mk
@@ -435,8 +435,9 @@
 # Phony target for only building what go/lem requires on target.
 .PHONY: build-art-target-golem
 # Also include libartbenchmark, we always include it when running golem.
+# libstdc++ is needed when building for ART_TARGET_LINUX.
 ART_TARGET_SHARED_LIBRARY_BENCHMARK := $(TARGET_OUT_SHARED_LIBRARIES)/libartbenchmark.so
-build-art-target-golem: dex2oat dalvikvm patchoat linker \
+build-art-target-golem: dex2oat dalvikvm patchoat linker libstdc++ \
                         $(TARGET_OUT)/etc/public.libraries.txt \
                         $(ART_TARGET_DEX_DEPENDENCIES) \
                         $(ART_TARGET_SHARED_LIBRARY_DEPENDENCIES) \