[Bug middle-end/61853] [4.9,4.10 Regression] ICE: SIGSEGV in store_field

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61853

--- Comment #5 from John David Anglin <danglin at gcc dot gnu.org> ---
These are arguments to expand_assignment:

(gdb) p debug_tree(to)
 <mem_ref 0xf722d558
    type <real_type 0xfad06ba0 double sizes-gimplified asm_written type_6 DF
        size <integer_cst 0xfacf4378 constant 64>
        unit size <integer_cst 0xfacf4390 constant 8>
        align 64 symtab -85994080 alias set 8 canonical type 0xfad06ba0
precision 64
        pointer_to_this <pointer_type 0xfad06cc0> reference_to_this
<reference_type 0xfa644f60>>

    arg 0 <addr_expr 0xf722d540
        type <pointer_type 0xf7cd3300 type <record_type 0xfab45600 Energy>
            public unsigned SI
            size <integer_cst 0xfacf4318 constant 32>
            unit size <integer_cst 0xfacf4330 constant 4>
            align 32 symtab 0 alias set -1 canonical type 0xf9a44540>

        arg 0 <result_decl 0xf6feb960 D.88242 type <record_type 0xfab45600
Energy>
            used ignored regdecl DF file ConstituentParticleData.h line 57 col
18 size <integer_cst 0xfacf4378 64> unit size <integer_cst 0xfacf4390 8>
            align 64 context <function_decl 0xf7d16980
_ZTv0_n64_NK6ThePEG23ConstituentParticleData15constituentMassEv>
            (parallel:BLK [
        (expr_list:REG_DEP_TRUE (reg:DI 101 [ <retval> ])
            (const_int 0 [0]))
    ])>>
    arg 1 <integer_cst 0xf6f188d0 type <pointer_type 0xf9a44540> constant 0>>
$1 = void
(gdb) p debug_tree(from)
 <ssa_name 0xf6f412d0
    type <real_type 0xfad06ba0 double sizes-gimplified asm_written type_6 DF
        size <integer_cst 0xfacf4378 constant 64>
        unit size <integer_cst 0xfacf4390 constant 8>
        align 64 symtab -85994080 alias set 8 canonical type 0xfad06ba0
precision 64
        pointer_to_this <pointer_type 0xfad06cc0> reference_to_this
<reference_type 0xfa644f60>>
    visited var <var_decl 0xf6c31b00 SR.222>def_stmt SR.222_7 = MEM[(const
struct ConstituentParticleData *)_2 + 8B];

    version 7>
$2 = void

public:

  /**
   * Return the constituent mass of this parton.
   */
  virtual Energy constituentMass() const { return theConstituentMass; }