misc/cgo/testcshared: restore gofrontend-local changes

    
    They were lost when the files were moved in the update to Go1.13beta1.
    These changes should be made in the master repo for the 1.14 release,
    as riscv64 support is added there.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194343

From-SVN: r275551

gcc/go/gofrontend/MERGE

-03fa49394bb4b37453795bef3119e5b40c929aee
+c6097f269d2b3dbfd5204cf7e3d0b9f8d7ec2b5e
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/misc/cgo/testcshared/testdata/libgo2/dup2.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux,!arm64 netbsd openbsd
+// +build darwin dragonfly freebsd linux,!arm64,!riscv64 netbsd openbsd
 
 package main
 

libgo/misc/cgo/testcshared/testdata/libgo2/dup3.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux,arm64
+// +build linux,arm64 linux,riscv64
 
 package main