Fix void foo(..) => ... to use { } instead.

sdk/lib/io/platform_impl.dart

Index: sdk/lib/io/platform_impl.dart
diff --git a/sdk/lib/io/platform_impl.dart b/sdk/lib/io/platform_impl.dart
index d7e722f22d07cb183201a1265159e18aeeb95707..8c9d30c027cd3085a7d3193177175b2ce8279c1e 100644
--- a/sdk/lib/io/platform_impl.dart
+++ b/sdk/lib/io/platform_impl.dart
@@ -109,8 +109,8 @@ class _CaseInsensitiveStringMap<V> implements Map<String, V> {
     other.forEach((key, value) => this[key.toUpperCase()] = value);
   }
   V remove(String key) => _map.remove(key.toUpperCase());
-  void clear() => _map.clear();
-  void forEach(void f(String key, V value)) => _map.forEach(f);
+  void clear() { _map.clear(); }
+  void forEach(void f(String key, V value)) { _map.forEach(f); }
   Iterable<String> get keys => _map.keys;
   Iterable<V> get values => _map.values;
   int get length => _map.length;