The encoding needs to be applied if the decl is not an alias: both a NULL
summary *OR* the decl alias flag is false.  This patch updates the
earlier fix to continue with the encoding selection if the summary is
NULL.

gcc/ChangeLog:
	* config/rs6000/rs6000.c (rs6000_xcoff_encode_section_info):
	Proceed if no symbol summary or the symbol alias flag is false.