Add ShadowBench

Drop -O3 & -ffast-math as they don't
help on clang and just hit SIGBUS issues

Change-Id: I8e9a8f4cd9ddf136103a6b7f69902e9f3a730c57
diff --git a/libs/hwui/Vector.h b/libs/hwui/Vector.h
index 7c3f2fd..6367dbd 100644
--- a/libs/hwui/Vector.h
+++ b/libs/hwui/Vector.h
@@ -135,8 +135,8 @@
     }
 
 
-    void dump() {
-        ALOGD("Vector3[%.2f, %.2f, %.2f]", x, y, z);
+    void dump(const char* label = "Vector3") const {
+        ALOGD("%s[%.2f, %.2f, %.2f]", label, x, y, z);
     }
 };