[gcc r12-7266] libbacktrace: initialize DWARF 5 fields of unit

[Ian Lance Taylor]

https://gcc.gnu.org/g:6d66bd25dc84e362f56ffe66667f6c9017ba73d0

commit r12-7266-g6d66bd25dc84e362f56ffe66667f6c9017ba73d0
Author: Ian Lance Taylor <iant@golang.org>
Date:   Wed Feb 16 11:35:00 2022 -0800

    libbacktrace: initialize DWARF 5 fields of unit
    
    When I added the fields in 2019-12-13 I forgot to initialize them.
    
            * dwarf.c (build_address_map): Initialize DWARF 5 fields of unit.

Diff:
---
 libbacktrace/dwarf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libbacktrace/dwarf.c b/libbacktrace/dwarf.c
index c0bae0e501e..2158bc14065 100644
--- a/libbacktrace/dwarf.c
+++ b/libbacktrace/dwarf.c
@@ -2221,6 +2221,9 @@ build_address_map (struct backtrace_state *state, uintptr_t base_address,
       u->comp_dir = NULL;
       u->abs_filename = NULL;
       u->lineoff = 0;
+      u->str_offsets_base = 0;
+      u->addr_base = 0;
+      u->rnglists_base = 0;
 
       /* The actual line number mappings will be read as needed.  */
       u->lines = NULL;