glsl: Strip arrayness from ir_type_dereference_variable too

glsl: Strip arrayness from ir_type_dereference_variable too

If the thing being dereferenced is a record or an array of records, it
should be treated as row-major.  The ir_type_derference_record path
already does this, and I think I intended to do the same for this path
in b17a4d5d.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83741
Cc: mesa-stable@lists.freedesktop.org