Re: PR28149, debug info with wrong file association

Re: PR28149, debug info with wrong file association

Fixes segfaults when building aarch64-linux kernel, due to only doing
part of the work necessary when allocating file numbers late.  I'd
missed looping over subsegments, which resulted in some u.filename
entries left around and later interpreted as u.view.

	PR 28149
	* dwarf2dbg.c (purge_generated_debug): Iterate over subsegs too.
	(dwarf2_finish): Call do_allocate_filenum for all subsegs too,
	in a separate loop before subsegs are chained.