Fix dw2-icycle.exp -fsanitize=address GDB crash.

Fix dw2-icycle.exp -fsanitize=address GDB crash.

binutils readelf -wi:
 <4><a2>: Abbrev Number: 26 (DW_TAG_inlined_subroutine)
    <a3>   DW_AT_abstract_origin: <0x5a>
    <a7>   DW_AT_low_pc      : 0x400590
    <ab>   DW_AT_high_pc     : 0x4
    <af>   DW_AT_call_file   : 1
    <b0>   DW_AT_call_line   : 20
    <b1>   DW_AT_sibling     : <0xb8>
 <2><b8>: Abbrev Number: 35 (DW_TAG_inlined_subroutine)
    <b9>   DW_AT_abstract_origin: <0x5a>
    <bd>   DW_AT_low_pc      : 0x400590
    <c1>   DW_AT_high_pc     : 0x4
    <c5>   DW_AT_call_file   : 1
    <c6>   DW_AT_call_line   : 29

<b1> DW_AT_sibling points to the next DIE - but that DIE is 2 levels
upwards - definitely not a sibling.  This confuses GDB up to a crash:

==32143== ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6024000198ac at pc 0xb4d104 bp 0x7fff63e96e70 sp
0x7fff63e96e60
READ of size 1 at 0x6024000198ac thread T0
    #0 0xb4d103 in read_unsigned_leb128 (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0xb4d103)
    #1 0xb15f3c in peek_die_abbrev (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0xb15f3c)
    #2 0xb46185 in load_partial_dies (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0xb46185)
    #3 0xb103fb in process_psymtab_comp_unit_reader (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0xb103fb)
    #4 0xb0d2a9 in init_cutu_and_read_dies (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0xb0d2a9)
    #5 0xb1115f in process_psymtab_comp_unit (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0xb1115f)
    #6 0xb1235f in dwarf2_build_psymtabs_hard (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0xb1235f)
    #7 0xb05536 in dwarf2_build_psymtabs (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0xb05536)
    #8 0x86d5a5 in read_psyms (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0x86d5a5)
    #9 0x9b1c37 in require_partial_symbols (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0x9b1c37)
    #10 0x9bf2d0 in read_symbols (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0x9bf2d0)
    #11 0x9c014c in syms_from_objfile_1 (/home/jkratoch/redhat/gdb-clean/gdb/gdb+0x9c014c)

gdb/testsuite/
2014-02-25  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix dw2-icycle.exp -fsanitize=address GDB crash.
	* gdb.dwarf2/dw2-icycle.S: Remove all DW_AT_sibling.

Message-ID: <20140224201011.GA28926@host2.jankratochvil.net>