Flush denorm half floats to zero.

src/core/SkSpanProcs.cpp

Index: src/core/SkSpanProcs.cpp
diff --git a/src/core/SkSpanProcs.cpp b/src/core/SkSpanProcs.cpp
index b2e9914a1784352a0b8825a79b9d5c4567d28201..32237d5f0329296aae25a55430878b03c5844f98 100644
--- a/src/core/SkSpanProcs.cpp
+++ b/src/core/SkSpanProcs.cpp
@@ -42,7 +42,7 @@ static void load_f16(const SkPixmap& src, int x, int y, SkPM4f span[], int count
     SkASSERT(src.addr64(x + count - 1, y));
 
     for (int i = 0; i < count; ++i) {
-        SkHalfToFloat_finite(addr[i]).store(span[i].fVec);
+        SkHalfToFloat_finite_ftz(addr[i]).store(span[i].fVec);
     }
 }