Disable babel-loader's cacheCompression (facebook#7633)

Author: jleclanche

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

@@ -404,7 +404,8 @@ module.exports = function(webpackEnv) {
                 // It enables caching results in ./node_modules/.cache/babel-loader/
                 // directory for faster rebuilds.
                 cacheDirectory: true,
-                cacheCompression: isEnvProduction,
+                // See #6846 for context on why cacheCompression is disabled
+                cacheCompression: false,
                 compact: isEnvProduction,
               },
             },
@@ -425,7 +426,8 @@ module.exports = function(webpackEnv) {
                   ],
                 ],
                 cacheDirectory: true,
-                cacheCompression: isEnvProduction,
+                // See #6846 for context on why cacheCompression is disabled
+                cacheCompression: false,
                 // @remove-on-eject-begin
                 cacheIdentifier: getCacheIdentifier(
                   isEnvProduction