Fix ICSS syntax in stylesheets (facebook#10511)

Author: thabemmz

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

@@ -529,6 +529,9 @@ module.exports = function (webpackEnv) {
                 sourceMap: isEnvProduction
                   ? shouldUseSourceMap
                   : isEnvDevelopment,
+                modules: {
+                  compileType: 'icss',
+                },
               }),
               // Don't consider CSS imports dead code even if the
               // containing package claims to have no side effects.
@@ -546,6 +549,7 @@ module.exports = function (webpackEnv) {
                   ? shouldUseSourceMap
                   : isEnvDevelopment,
                 modules: {
+                  compileType: 'module',
                   getLocalIdent: getCSSModuleLocalIdent,
                 },
               }),
@@ -562,6 +566,9 @@ module.exports = function (webpackEnv) {
                   sourceMap: isEnvProduction
                     ? shouldUseSourceMap
                     : isEnvDevelopment,
+                  modules: {
+                    compileType: 'icss',
+                  },
                 },
                 'sass-loader'
               ),
@@ -582,6 +589,7 @@ module.exports = function (webpackEnv) {
                     ? shouldUseSourceMap
                     : isEnvDevelopment,
                   modules: {
+                    compileType: 'module',
                     getLocalIdent: getCSSModuleLocalIdent,
                   },
                 },