Improve wording of comments

Most of the time, these methods are called from actual methods defined
from columns in the schema, not from method_missing, so the current
wording is misleading.

activemodel/lib/active_model/attributes.rb

@@ -91,7 +91,7 @@ def attribute(attr_name)
         @attributes.fetch_value(name)
       end
 
-      # Handle *= for method_missing.
+      # Dispatch target for <tt>*=</tt> attribute methods.
       def attribute=(attribute_name, value)
         write_attribute(attribute_name, value)
       end

activemodel/lib/active_model/dirty.rb

@@ -165,17 +165,17 @@ def changed
       mutations_from_database.changed_attribute_names
     end
 
-    # Handles <tt>*_changed?</tt> for +method_missing+.
+    # Dispatch target for <tt>*_changed?</tt> attribute methods.
     def attribute_changed?(attr_name, **options) # :nodoc:
       mutations_from_database.changed?(attr_name.to_s, options)
     end
 
-    # Handles <tt>*_was</tt> for +method_missing+.
+    # Dispatch target for <tt>*_was</tt> attribute methods.
     def attribute_was(attr_name) # :nodoc:
       mutations_from_database.original_value(attr_name.to_s)
     end
 
-    # Handles <tt>*_previously_changed?</tt> for +method_missing+.
+    # Dispatch target for <tt>*_previously_changed?</tt> attribute methods.
     def attribute_previously_changed?(attr_name) # :nodoc:
       mutations_before_last_save.changed?(attr_name.to_s)
     end
@@ -253,22 +253,22 @@ def mutations_before_last_save
         @mutations_before_last_save ||= ActiveModel::NullMutationTracker.instance
       end
 
-      # Handles <tt>*_change</tt> for +method_missing+.
+      # Dispatch target for <tt>*_change</tt> attribute methods.
       def attribute_change(attr_name)
         mutations_from_database.change_to_attribute(attr_name.to_s)
       end
 
-      # Handles <tt>*_previous_change</tt> for +method_missing+.
+      # Dispatch target for <tt>*_previous_change</tt> attribute methods.
       def attribute_previous_change(attr_name)
         mutations_before_last_save.change_to_attribute(attr_name.to_s)
       end
 
-      # Handles <tt>*_will_change!</tt> for +method_missing+.
+      # Dispatch target for <tt>*_will_change!</tt> attribute methods.
       def attribute_will_change!(attr_name)
         mutations_from_database.force_change(attr_name.to_s)
       end
 
-      # Handles <tt>restore_*!</tt> for +method_missing+.
+      # Dispatch target for <tt>restore_*!</tt> attribute methods.
       def restore_attribute!(attr_name)
         attr_name = attr_name.to_s
         if attribute_changed?(attr_name)

activerecord/lib/active_record/attribute_methods/before_type_cast.rb

@@ -65,7 +65,7 @@ def attributes_before_type_cast
 
       private
 
-        # Handle *_before_type_cast for method_missing.
+        # Dispatch target for <tt>*_before_type_cast</tt> attribute methods.
         def attribute_before_type_cast(attribute_name)
           read_attribute_before_type_cast(attribute_name)
         end

activerecord/lib/active_record/attribute_methods/query.rb

@@ -32,7 +32,7 @@ def query_attribute(attr_name)
       end
 
       private
-        # Handle *? for method_missing.
+        # Dispatch target for <tt>*?</tt> attribute methods.
         def attribute?(attribute_name)
           query_attribute(attribute_name)
         end

activerecord/lib/active_record/attribute_methods/write.rb

@@ -58,7 +58,7 @@ def write_attribute_without_type_cast(attr_name, value)
           value
         end
 
-        # Handle *= for method_missing.
+        # Dispatch target for <tt>*=</tt> attribute methods.
         def attribute=(attribute_name, value)
           _write_attribute(attribute_name, value)
         end