gccgo: segmentation fault (4)

[dvyukov]

gccgo crashes on the following input:

package a
var a = func({-chan<-a<-})

go1: internal compiler error: Segmentation fault
0xb4170f crash_signal
    ../../gcc/toplev.c:360
0x64f48a Send_statement::do_flatten(Gogo*, Named_object*, Block*, Statement_inserter*)
    ../../gcc/go/gofrontend/statements.cc:4391
0x610f8c Statement::flatten(Gogo*, Named_object*, Block*, Statement_inserter*)
    ../../gcc/go/gofrontend/statements.h:320
0x610f8c Flatten::statement(Block*, unsigned long*, Statement*)
    ../../gcc/go/gofrontend/gogo.cc:3834
0x64edb4 Statement::traverse(Block*, unsigned long*, Traverse*)
    ../../gcc/go/gofrontend/statements.cc:44
0x613e5d Block::traverse(Traverse*)
    ../../gcc/go/gofrontend/gogo.cc:5741
0x61409e Function::traverse(Traverse*)
    ../../gcc/go/gofrontend/gogo.cc:4863
0x6140f0 Flatten::function(Named_object*)
    ../../gcc/go/gofrontend/gogo.cc:3799
0x616a41 Bindings::traverse(Traverse*, bool)
    ../../gcc/go/gofrontend/gogo.cc:7516
0x616b71 Gogo::traverse(Traverse*)
    ../../gcc/go/gofrontend/gogo.cc:2491
0x616dcf Gogo::flatten()
    ../../gcc/go/gofrontend/gogo.cc:3900
0x6105db go_parse_input_files(char const**, unsigned int, bool, bool)
    ../../gcc/go/gofrontend/go.cc:139
0x60c32f go_langhook_parse_file
    ../../gcc/go/go-lang.c:304

gcc version 6.0.0 2015070 (experimental) (GCC)

[dvyukov]

@paranoiacblack

[gopherbot]

CL https://golang.org/cl/12795 mentions this issue.

[gopherbot]

CL https://golang.org/cl/13097 mentions this issue.