Add Sk4f_RoundToInt

src/opts/SkNx_sse.h

Index: src/opts/SkNx_sse.h
diff --git a/src/opts/SkNx_sse.h b/src/opts/SkNx_sse.h
index 9751c4db9141246681d8905bbaf2f5220fb293c2..6a64cc86144b826b3d8f3fc20661566b9fa2175f 100644
--- a/src/opts/SkNx_sse.h
+++ b/src/opts/SkNx_sse.h
@@ -377,4 +377,12 @@ template<> /*static*/ inline Sk4b SkNx_cast<uint8_t, uint16_t>(const Sk4h& src)
     return _mm_packus_epi16(src.fVec, src.fVec);
 }
 
+template<> inline Sk4b SkNx_cast<uint8_t, int>(const Sk4i& src) {
+    return _mm_packus_epi16(_mm_packus_epi16(src.fVec, src.fVec), src.fVec);
+}
+
+static inline Sk4i Sk4f_round(const Sk4f& x) {
+    return _mm_cvtps_epi32(x.fVec);
+}
+
 #endif//SkNx_sse_DEFINED