The following snippet make gdc crash

interface I
{
  void f();
}

class C: I
{
  void f();
}

int main()
{
  return 0;
}

gdc outputs

"tmp/test.d: In member function ‘_DT16_D4test1C1fMFZv’:
/tmp/test.d:1:0: internal compiler error: Segmentation fault
 interface I
 ^
0xab44df crash_signal
        ../../src/gcc/toplev.c:383
0x88e61a fold_build_pointer_plus_hwi_loc(unsigned int, tree_node*, long)
        ../../src/gcc/fold-const.c:16283
0x7c669a thunk_adjust
        ../../src/gcc/cgraphunit.c:1407
0x7c780f cgraph_node::expand_thunk(bool, bool)
        ../../src/gcc/cgraphunit.c:1665
0x73aad2 finish_thunk(tree_node*, tree_node*, int)
        ../../src/gcc/d/d-objfile.cc:2151
0x72e10c FuncDeclaration::toThunkSymbol(int)
        ../../src/gcc/d/d-decls.cc:522
0x738dfb ClassDeclaration::toObjFile(bool)
        ../../src/gcc/d/d-objfile.cc:460
0x73bfb6 Module::genobjfile(bool)
        ../../src/gcc/d/d-objfile.cc:1433
0x72d097 d_parse_file()
        ../../src/gcc/d/d-lang.cc:1183
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-5/README.Bugs> for instructions.
"

Versions:
"gdc --version" outputs "gdc (Debian 5.2.1-23) 5.2.1 20151028"
"head /etc/debian_version" outputs : "stretch/sid"