alias.c: find_base_decl: TREE_CODE_CLASS of '3'

[Jeffrey D. Oldham]

In gcc/alias.c, find_base_decl, the switch on TREE_CODE_CLASS (TREE_CODE 
(t)) has a case '3'.  How can '3' be a valid tree code class?  '1' and 
'2' are valid tree code classes.

-- 
Jeffrey D. Oldham
oldham@codesourcery.com