Temporarily use -fstack-protector for the read barrier config.

Instead of -fstack-protector-strong.

To avoid a major performance regression.

Bug: 26744236
Bug: 12687968

Change-Id: I299247589e2bb6939393d30bdc54c15ce0f04b2a
diff --git a/build/Android.common_build.mk b/build/Android.common_build.mk
index eec471e..dc53853 100644
--- a/build/Android.common_build.mk
+++ b/build/Android.common_build.mk
@@ -318,6 +318,10 @@
   art_cflags += -DART_READ_BARRIER_TYPE_IS_$(ART_READ_BARRIER_TYPE)=1
   art_asflags += -DART_USE_READ_BARRIER=1
   art_asflags += -DART_READ_BARRIER_TYPE_IS_$(ART_READ_BARRIER_TYPE)=1
+
+  # Temporarily override -fstack-protector-strong with -fstack-protector to avoid a major
+  # slowdown with the read barrier config. b/26744236.
+  art_cflags += -fstack-protector
 endif
 
 ifeq ($(ART_USE_TLAB),true)