Defork RectangleEdges.h

Problem Description

Creating issue to track deforking of this file

Recent integration came across this PR (https://github.com/facebook/react-native/commit/56e9aa369f5c13af38cf80ba47e9eb29d835ec89) added these lines of code to RectangleEdges.h

struct RectangleEdges {
 ...
 static RectangleEdges<T> const ZERO;
};

template <typename T>
constexpr RectangleEdges<T> const RectangleEdges<T>::ZERO = {};

which created these C2370 redefinition; different stage class errors

Removing the constexpr identifier solves the problem but not sure that's the solution. I think it has to do with how we load in header files into our project since this did not break upstream.

Steps To Reproduce

1. Delete forked RectangleEdges.h file in RNW repo
2. Try to build the playground solution

Expected Results

Should build fine

CLI version

npx react-native --version

Environment

npx react-native info

Target Platform Version

10.0.19041

Target Device(s)

Desktop

Visual Studio Version

Visual Studio 2019

Build Configuration

Debug

Snack, code example, screenshot, or link to a repository

No response