ubsan shift fixes

src/core/SkFDot6.h

Index: src/core/SkFDot6.h
diff --git a/src/core/SkFDot6.h b/src/core/SkFDot6.h
index 3da753da413180de77c162092c4fc98f64d02239..b5367298298cd29f3b85d7577f13e914446e314e 100644
--- a/src/core/SkFDot6.h
+++ b/src/core/SkFDot6.h
@@ -56,9 +56,9 @@ inline SkFDot6 SkScalarRoundToFDot6(SkScalar x, int shift = 0)
 #define SkFixedToFDot6(x)   ((x) >> 10)
 
 inline SkFixed SkFDot6ToFixed(SkFDot6 x) {
-    SkASSERT((x << 10 >> 10) == x);
+    SkASSERT((SkLeftShift(x, 10) >> 10) == x);
 
-    return x << 10;
+    return SkLeftShift(x, 10);
 }
 
 #define SkScalarToFDot6(x)  (SkFDot6)((x) * 64)
@@ -68,7 +68,7 @@ inline SkFixed SkFDot6Div(SkFDot6 a, SkFDot6 b) {
     SkASSERT(b != 0);
 
     if (a == (int16_t)a) {
-        return (a << 16) / b;
+        return SkLeftShift(a, 16) / b;
     } else {
         return SkFixedDiv(a, b);
     }