The only two use cases of the obtained Language object are for Language::getNsText( NS_MEDIAWIKI ) and Language::ucfirst()

For the first one, this functionality should go to NamespaceInfo and use dependency injection.

For the ucfirst, it's guarded in a feature flag $this->mUcfirst defaults to false, and no subclasses use this feature. I suggest we can remove this.

		if ( $this->mUcfirst ) {
			foreach ( $ret as $k => $v ) {
				$ret[$this->mLangObj->ucfirst( $k )] = $this->mLangObj->ucfirst( $v );
			}
		}