Add aria-label to floatingActionButton (#8574)

app/javascript/mastodon/features/ui/components/columns_area.js

 import React from 'react';
 import PropTypes from 'prop-types';
-import { injectIntl } from 'react-intl';
+import { defineMessages, injectIntl } from 'react-intl';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import ImmutablePureComponent from 'react-immutable-pure-component';
 
@@ -29,6 +29,10 @@ const componentMap = {
   'LIST': ListTimeline,
 };
 
+const messages = defineMessages({
+  publish: { id: 'compose_form.publish', defaultMessage: 'Toot' },
+});
+
 const shouldHideFAB = path => path.match(/^\/statuses\//);
 
 @component => injectIntl(component, { withRef: true })
@@ -149,14 +153,14 @@ export default class ColumnsArea extends ImmutablePureComponent {
   }
 
   render () {
-    const { columns, children, singleColumn, isModalOpen } = this.props;
+    const { columns, children, singleColumn, isModalOpen, intl } = this.props;
     const { shouldAnimate } = this.state;
 
     const columnIndex = getIndex(this.context.router.history.location.pathname);
     this.pendingIndex = null;
 
     if (singleColumn) {
-      const floatingActionButton = shouldHideFAB(this.context.router.history.location.pathname) ? null : <Link key='floating-action-button' to='/statuses/new' className='floating-action-button'><i className='fa fa-pencil' /></Link>;
+      const floatingActionButton = shouldHideFAB(this.context.router.history.location.pathname) ? null : <Link key='floating-action-button' to='/statuses/new' className='floating-action-button' aria-label={intl.formatMessage(messages.publish)}><i className='fa fa-pencil' /></Link>;
 
       return columnIndex !== -1 ? [
         <ReactSwipeableViews key='content' index={columnIndex} onChangeIndex={this.handleSwipe} onTransitionEnd={this.handleAnimationEnd} animateTransitions={shouldAnimate} springConfig={{ duration: '400ms', delay: '0s', easeFunction: 'ease' }} style={{ height: '100%' }}>