asan: _bfd_stab_section_find_nearest_line segv

[Alan Modra]

The segv was on "info->strs[strsize - 1] = 0;" with strsize zero.  OK,
if strsize is zero we don't have any filenames in stabs so no useful
info.

	* syms.c (_bfd_stab_section_find_nearest_line): Exit if either
	stabsize or strsize is zero.

diff --git a/bfd/syms.c b/bfd/syms.c
index ec62f3457ca..e8077f59bf0 100644
--- a/bfd/syms.c
+++ b/bfd/syms.c
@@ -1027,6 +1027,9 @@ _bfd_stab_section_find_nearest_line (bfd *abfd,
 		 ? info->strsec->rawsize
 		 : info->strsec->size);
 
+      if (stabsize == 0 || strsize == 0)
+	goto out;
+
       if (!bfd_malloc_and_get_section (abfd, info->stabsec, &info->stabs))
 	goto out;
       if (!bfd_malloc_and_get_section (abfd, info->strsec, &info->strs))

-- 
Alan Modra
Australia Development Lab, IBM