Add gnu global outputs to .gitignore

GNU Global outputs can be safely ignored.

ChangeLog:

2020-12-02  Enze Li  <lienze2010@hotmail.com>

	* .gitignore: Add gnu global outputs.

Change-Id: I04ce68ab3279426195793adb56f834a34ee72ea2

.gitignore

@@ -48,6 +48,12 @@ compile_commands.json
 perf.data
 perf.data.old
 
+# gnu global files
+GPATH
+GRTAGS
+GTAGS
+GSYMS
+
 # ignore core files, but not java/net/protocol/core/
 core
 !core/

ChangeLog

+2020-12-02  Enze Li  <lienze2010@hotmail.com>
+
+	* .gitignore: Add gnu global outputs.
+
 2020-12-02  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* .gitignore: Sync with gcc.