re PR go/79443 (libgo/math test fails on s390x (undefined symbols cosh, sinh, tanh, hasVX))

PR go/79443
    libgo: fix some s390x tests
    
    Add `+build ignore` to ignore tests that rely on s390x assembly code
    not yet implemented for gccgo.
    
    Fixes GCC PR 79443.
    
    Reviewed-on: https://go-review.googlesource.com/36909

From-SVN: r245397

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-7fa4eb4b7a32953c2e838f1b0c684a6733172b43
+c3935e1f20ad5b1d4c41150f11fb266913c04df7
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/crypto/sha256/fallback_test.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build ignore
 // +build s390x
 
 package sha256

libgo/go/math/export_s390x_test.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build ignore
+
 package math
 
 // Export internal functions and variable for testing.