Fabric: AttributedString::operator==() now checks layoutMetrics for being equal

Summary:
The sizes of attachments are legit parts of `AttributedString`s identity, so we need to incorporate it into the equality test.
We need that to make measurement cache work correctly with inline views.

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: mdvacca

Differential Revision: D20151505

fbshipit-source-id: ae47c24a753eab1e497fcfaa93de557ffb30d874

ReactCommon/fabric/attributedstring/AttributedString.cpp

@@ -26,8 +26,16 @@ bool Fragment::isAttachment() const {
 }
 
 bool Fragment::operator==(const Fragment &rhs) const {
-  return std::tie(string, textAttributes, parentShadowView.tag) ==
-      std::tie(rhs.string, rhs.textAttributes, rhs.parentShadowView.tag);
+  return std::tie(
+             string,
+             textAttributes,
+             parentShadowView.tag,
+             parentShadowView.layoutMetrics) ==
+      std::tie(
+             rhs.string,
+             rhs.textAttributes,
+             rhs.parentShadowView.tag,
+             rhs.parentShadowView.layoutMetrics);
 }
 
 bool Fragment::operator!=(const Fragment &rhs) const {