ld: Add a before_plugin_all_symbols_read hook

[Alan Modra]

	* testsuite/ld-plugin/pr28849.d: Adjust for powerpc64 function
	descriptors.

diff --git a/ld/testsuite/ld-plugin/pr28849.d b/ld/testsuite/ld-plugin/pr28849.d
index a1f90c1ac8c..8ea4e3fde43 100644
--- a/ld/testsuite/ld-plugin/pr28849.d
+++ b/ld/testsuite/ld-plugin/pr28849.d
@@ -1,3 +1,3 @@
 #...
-[0-9a-f]+ T _?should_be_dynamic_in_exec
+.* _?should_be_dynamic_in_exec
 #pass

-- 
Alan Modra
Australia Development Lab, IBM