Set dwarf2 stash pointer earlier

[Alan Modra]

This fixes a memory leak in the vanishingly rare cases (found by
fuzzers of course) when something goes wrong in the save_section_vma,
htab_create_alloc or alloc_trie_leaf calls before *pinfo is written.
If *pinfo is not written, _bfd_dwarf2_cleanup_debug_info won't be able
to free that memory.

	* dwarf2.c (_bfd_dwarf2_slurp_debug_info): Save stash pointer
	on setting up stash.

diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
index f689eebbd88..bd431805d2a 100644
--- a/bfd/dwarf2.c
+++ b/bfd/dwarf2.c
@@ -5408,6 +5408,7 @@ _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
       stash = (struct dwarf2_debug *) bfd_zalloc (abfd, amt);
       if (! stash)
 	return false;
+      *pinfo = stash;
     }
   stash->orig_bfd = abfd;
   stash->debug_sections = debug_sections;
@@ -5433,8 +5434,6 @@ _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
   if (!stash->alt.trie_root)
     return false;
 
-  *pinfo = stash;
-
   if (debug_bfd == NULL)
     debug_bfd = abfd;
 

-- 
Alan Modra
Australia Development Lab, IBM