Add braces around single-statement if/foreach

csharp/src/Google.Protobuf/ExtensionRegistry.cs

@@ -90,7 +90,9 @@ namespace Google.Protobuf
             ProtoPreconditions.CheckNotNull(extensions, nameof(extensions));
 
             foreach (var extension in extensions)
+            {
                 Add(extension);
+            }
         }
 
         /// <summary>
@@ -120,9 +122,13 @@ namespace Google.Protobuf
         {
             ProtoPreconditions.CheckNotNull(array, nameof(array));
             if (arrayIndex < 0 || arrayIndex >= array.Length)
+            {
                 throw new ArgumentOutOfRangeException(nameof(arrayIndex));
+            }
             if (array.Length - arrayIndex < Count)
+            {
                 throw new ArgumentException("The provided array is shorter than the number of elements in the registry");
+            }
 
             for (int i = 0; i < array.Length; i++)
             {

csharp/src/Google.Protobuf/Reflection/ExtensionCollection.cs

@@ -109,7 +109,9 @@ namespace Google.Protobuf.Reflection
 
                 IList<FieldDescriptor> _;
                 if (!declarationOrder.TryGetValue(descriptor.ExtendeeType, out _))
+                {
                     declarationOrder.Add(descriptor.ExtendeeType, new List<FieldDescriptor>());
+                }
 
                 declarationOrder[descriptor.ExtendeeType].Add(descriptor);
             }