build: add source-map-loader to webpack config

Author: justingrant

packages/react-scripts/config/webpack.config.js

@@ -376,6 +376,13 @@ module.exports = function (webpackEnv) {
           ],
           include: paths.appSrc,
         },
+        // Handle node_modules packages that contain sourcemaps
+        shouldUseSourceMap && {
+          enforce: 'pre',
+          exclude: /@babel(?:\/|\\{1,2})runtime/,
+          test: /\.(js|mjs|jsx|ts|tsx|css)$/,
+          use: 'source-map-loader',
+        },
         {
           // "oneOf" will traverse all following loaders until one will
           // match the requirements. When no loader matches it will fall