Disable shadow overdraw avoidance in the inverse clip case

The caster is effectivly transparent, so skip the optimization just as
is done for alpha < 1.0

Change-Id: I3d294222adf0137e20c1fb5808313d487e92e0a8
diff --git a/libs/hwui/OpenGLRenderer.h b/libs/hwui/OpenGLRenderer.h
index 054767e..2debd2e 100644
--- a/libs/hwui/OpenGLRenderer.h
+++ b/libs/hwui/OpenGLRenderer.h
@@ -210,7 +210,7 @@
     virtual status_t drawRects(const float* rects, int count, const SkPaint* paint);
 
     status_t drawShadow(const mat4& casterTransformXY, const mat4& casterTransformZ,
-            float casterAlpha, const SkPath* casterPerimeter);
+            float casterAlpha, bool casterUnclipped, const SkPath* casterPerimeter);
 
     virtual void resetShader();
     virtual void setupShader(SkiaShader* shader);