Avoid redundant `attribute_alias?` before `attribute_alias`

If we want to get alias resolved attribute finally, we can use
`attribute_alias` directly.

For that purpose, avoiding redundant `attribute_alias?` makes alias
attribute access 40% faster.

https://gist.github.com/kamipo/e427f080a27b46f50bc508fae3612a0e

Before (2c0729d8):

```
Warming up --------------------------------------
          user['id']   102.668k i/100ms
      user['new_id']    80.660k i/100ms
        user['name']    99.368k i/100ms
    user['new_name']    81.626k i/100ms
Calculating -------------------------------------
          user['id']      1.431M (± 4.0%) i/s -      7.187M in   5.031985s
      user['new_id']      1.042M (± 4.2%) i/s -      5.243M in   5.039858s
        user['name']      1.406M (± 5.6%) i/s -      7.055M in   5.036743s
    user['new_name']      1.074M (± 3.6%) i/s -      5.387M in   5.024152s
```

After (this change):

```
Warming up --------------------------------------
          user['id']   109.775k i/100ms
      user['new_id']   103.303k i/100ms
        user['name']   105.988k i/100ms
    user['new_name']    99.618k i/100ms
Calculating -------------------------------------
          user['id']      1.520M (± 6.7%) i/s -      7.574M in   5.011496s
      user['new_id']      1.485M (± 6.2%) i/s -      7.438M in   5.036252s
        user['name']      1.538M (± 5.4%) i/s -      7.737M in   5.049765s
    user['new_name']      1.516M (± 4.6%) i/s -      7.571M in   5.007293s
```

1 files changed, 7 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 1ff7ee4d89..adfd564695 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -664,8 +664,13 @@ module ActiveRecord
       raise ActiveRecordError, "cannot update a new record" if new_record?
       raise ActiveRecordError, "cannot update a destroyed record" if destroyed?
 
+      attributes = attributes.transform_keys do |key|
+        name = key.to_s
+        self.class.attribute_aliases[name] || name
+      end
+
       attributes.each_key do |key|
-        verify_readonly_attribute(key.to_s)
+        verify_readonly_attribute(key)
       end
 
       id_in_database = self.id_in_database
@@ -853,7 +858,7 @@ module ActiveRecord
 
       attribute_names = timestamp_attributes_for_update_in_model
       attribute_names |= names.map!(&:to_s).map! { |name|
-        self.class.attribute_alias?(name) ? self.class.attribute_alias(name) : name
+        self.class.attribute_aliases[name] || name
       }
 
       unless attribute_names.empty?