Doug pointed out a while ago that in the final dwz -m patch, nothing
ever set symtab::user.
This patch fixes this oversight and adds a test case showing why it is
important.
Built and regtested (both ways) on x86-64 Fedora 18.
The new test unconditionally tests the partial unit machinery, which I
think is an added plus.
* dwarf2read.c (recursively_compute_inclusions): Add
"immediate_parent" argument. Set symtab's "user" field
if not set.
(compute_symtab_includes): Update.
* gdb.dwarf2/dwz.exp: New file.
