mesa: Add a dist hook to remove .gitignore files from distribution.
diff --git a/Makefile.am b/Makefile.am
index 7645176..61a7ad1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -110,3 +110,8 @@
 	@-sha256sum $(PACKAGE_NAME).zip
 
 .PHONY: tarballs checksums
+
+# We list some directories in EXTRA_DIST, but don't actually want to include
+# the .gitignore files in the tarball.
+dist-hook:
+	find $(distdir) -name .gitignore -exec $(RM) {} +