The attached file seems to isolate the difference. It seems (*runtime.Func).Name is rather different with gccgo and without:
$ go run funcname.go
launchpad.net/gocheck.Suite
launchpad.net/gocheck.(*CheckerInfo).Info
$ go run -compiler gccgo funcname.go
launchpad.net_gocheck.Suite
main.$thunk0
The attached file seems to isolate the difference. It seems (*runtime. Func).Name is rather different with gccgo and without:
$ go run funcname.go net/gocheck. Suite net/gocheck. (*CheckerInfo) .Info net_gocheck. Suite
launchpad.
launchpad.
$ go run -compiler gccgo funcname.go
launchpad.
main.$thunk0