RELEASING: Add note on checking for local symbol PLT entries.

(cherry picked from 4620b929ae commit)

RELEASING

@@ -18,6 +18,36 @@ Here are the steps to follow to create a new cairo release:
 	(But the tar file isn't actually ready yet, as we still have
 	some more steps to follow).
 
+2.a) Verify that there are no local symbol PLT entries.
+
+	XXX: Currently this is a manual step, but it would be nice to
+	get all the support for this integrated automatically into
+	make distcheck. (An alternative approach would automate the
+	generation of the aliases such as is done for fontconfig
+	rather than maintaining these manually with the slim_hidden
+	macros).
+
+	For now, here's what you need:
+
+	1. The elfutils package for your distribution
+	2. The relinfo.pl scritp available here:
+
+		http://people.freedesktop.org/~keithp/relinfo.pl
+
+	Then run the following command:
+
+		relinfo.pl src/.libs/libcairo.so
+
+	And ensure that it reports "0 for local syms". If not, then
+	run the following:
+
+		eu-readelf -r src/.libs/libcairo.so
+
+	And look for the symbols related to cairo in the relocation
+	section. For each of these, a call to slim_hidden_def and
+	slim_hidden_proto is needed in the cairo implementation in the
+	style of other similar calls.
+
 3) Fill out an entry in the NEWS file
 
 	Sift through the logs since the last release. This is most