optimize setRectFan and join -- from profiling drawText

include/core/SkPoint.h

Index: include/core/SkPoint.h
diff --git a/include/core/SkPoint.h b/include/core/SkPoint.h
index 6f32d98c751c3827a10e98b86810b130c2351edf..18b371f2ca3910274fc0520de772c87ef90075d2 100644
--- a/include/core/SkPoint.h
+++ b/include/core/SkPoint.h
@@ -212,7 +212,16 @@ struct SK_API SkPoint {
         v[2].set(r, b);
         v[3].set(r, t);
     }
-    void setRectFan(SkScalar l, SkScalar t, SkScalar r, SkScalar b, size_t stride);
+
+    void setRectFan(SkScalar l, SkScalar t, SkScalar r, SkScalar b, size_t stride) {
+        SkASSERT(stride >= sizeof(SkPoint));
+        
+        ((SkPoint*)((intptr_t)this + 0 * stride))->set(l, t);
+        ((SkPoint*)((intptr_t)this + 1 * stride))->set(l, b);
+        ((SkPoint*)((intptr_t)this + 2 * stride))->set(r, b);
+        ((SkPoint*)((intptr_t)this + 3 * stride))->set(r, t);
+    }
+    
 
     static void Offset(SkPoint points[], int count, const SkPoint& offset) {
         Offset(points, count, offset.fX, offset.fY);