C++ style enums 14/N: Overflow (#1398)

Summary:
X-link: https://github.com/facebook/react-native/pull/39537

Pull Request resolved: https://github.com/facebook/yoga/pull/1398

Moves internal usages of YGOverflow to Overflow

bypass-github-export-checks

Changelog: [Internal]

Reviewed By: rshest

Differential Revision: D49361843

fbshipit-source-id: 42161aa8a26f64f052587b861120cdad0290ae46

yoga/debug/NodeToString.cpp

@@ -170,8 +170,7 @@ void nodeToString(
     }
 
     if (style.overflow() != yoga::Node{}.getStyle().overflow()) {
-      appendFormattedString(
-          str, "overflow: %s; ", YGOverflowToString(style.overflow()));
+      appendFormattedString(str, "overflow: %s; ", toString(style.overflow()));
     }
 
     if (style.display() != yoga::Node{}.getStyle().display()) {