Fix compare icon render bug

src/vs/workbench/browser/media/icons.css

@@ -109,6 +109,7 @@ body[data-exploration^="icon-exploration"] .monaco-editor .debug-breakpoint-log,
 body[data-exploration^="icon-exploration"] .monaco-editor .peekview-widget .head .peekview-title .severity-icon,
 body[data-exploration^="icon-exploration"] .monaco-editor .margin-view-overlays .folding,
 body[data-exploration^="icon-exploration"] .monaco-workbench .explorer-action.save-all,
+body[data-exploration^="icon-exploration"] .monaco-workbench .part.editor > .content .editor-group-container > .title .editor-actions .action-label[data-title="workbench.action.compareEditor.previousChange"],
 body[data-exploration^="icon-exploration"] .monaco-panel-view .panel > .panel-header > .actions .action-label.icon[data-title="git.commit"],
 body[data-exploration^="icon-exploration"] .monaco-panel-view .panel > .panel-header > .actions .action-label.icon[data-title="git.refresh"],
 body[data-exploration^="icon-exploration"] .markers-panel .monaco-tl-contents .multiline-actions .action-label.octicon-chevron-up,