Update Go library to last weekly.

gcc/testsuite/go.test/test/chan/sieve2.go

gcc/testsuite/go.test/test/vectors.go

libgo/MERGE

libgo/Makefile.am

libgo/Makefile.in

libgo/go/archive/tar/common.go

libgo/go/archive/tar/reader.go

libgo/go/archive/tar/testdata/writer.tar

libgo/go/archive/tar/writer.go

libgo/go/archive/tar/writer_test.go

libgo/go/archive/zip/reader.go

libgo/go/archive/zip/reader_test.go

libgo/go/archive/zip/struct.go

libgo/go/archive/zip/writer.go

libgo/go/archive/zip/writer_test.go

libgo/go/asn1/asn1.go

libgo/go/asn1/asn1_test.go

libgo/go/asn1/marshal.go

libgo/go/big/int.go

libgo/go/big/int_test.go