libsysprof-gtk: add specialized symbol label for descendants

This allows us to provide a bit more context to things in the descendants
callgraph based on the symbol. Context switches get specialized highlight
as well as All Processes and Processes nodes.

src/libsysprof-gtk/sysprof-symbol-label-private.h

@@ -0,0 +1,38 @@
+/* sysprof-symbol-label-private.h
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+#include <sysprof-analyze.h>
+
+G_BEGIN_DECLS
+
+#define SYSPROF_TYPE_SYMBOL_LABEL (sysprof_symbol_label_get_type())
+
+G_DECLARE_FINAL_TYPE (SysprofSymbolLabel, sysprof_symbol_label, SYSPROF, SYMBOL_LABEL, GtkWidget)
+
+GtkWidget     *sysprof_symbol_label_new        (void);
+SysprofSymbol *sysprof_symbol_label_get_symbol (SysprofSymbolLabel *self);
+void           sysprof_symbol_label_set_symbol (SysprofSymbolLabel *self,
+                                                SysprofSymbol      *symbol);
+
+G_END_DECLS