gccgo: internal compiler error: in start_function (2) #12324

go1: internal compiler error: in start_function, at go/gofrontend/gogo.cc:1821
0x626dba Gogo::start_function(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, Function_type*, bool, Location)
    ../../gcc/go/gofrontend/gogo.cc:1821
0x64692b Parse::function_decl(bool)
    ../../gcc/go/gofrontend/parse.cc:2355
0x647343 Parse::program()
    ../../gcc/go/gofrontend/parse.cc:5689
0x60ede1 go_parse_input_files(char const**, unsigned int, bool, bool)
    ../../gcc/go/gofrontend/go.cc:73
0x60accf go_langhook_parse_file
    ../../gcc/go/go-lang.c:304