[Bug debug/65549] [5 Regression] crash in htab_hash_string with -flto

["trippels at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65549

--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Created attachment 35158
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35158&action=edit
reduced testcase

markus@x4 tmp % g++ -std=gnu++1y -flto -g -O2 -r -nostdlib tcp_client.ii
lto1: internal compiler error: Segmentation fault
0xa2766f crash_signal
        ../../gcc/gcc/toplev.c:383
0x10ed7b0 htab_hash_string
        ../../gcc/libiberty/hashtab.c:839
0x6e66df external_ref_hasher::hash(external_ref const*)
        ../../gcc/gcc/dwarf2out.c:7763
0x6e66df hash_table<external_ref_hasher, xcallocator,
false>::find_slot(external_ref const*, insert_option)
        ../../gcc/gcc/hash-table.h:652
0x6e66df lookup_external_ref
        ../../gcc/gcc/dwarf2out.c:7791
0x6e6770 optimize_external_refs_1
        ../../gcc/gcc/dwarf2out.c:7829
0x6e6797 optimize_external_refs_1
        ../../gcc/gcc/dwarf2out.c:7833
0x6e6c06 optimize_external_refs
        ../../gcc/gcc/dwarf2out.c:7882
0x6e6e3d output_comp_unit
        ../../gcc/gcc/dwarf2out.c:9122
0x70ac89 dwarf2out_finish
        ../../gcc/gcc/dwarf2out.c:24800
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