re PR go/68072 (malformed DWARF TagVariable entry)

	PR go/68072
    cmd/cgo: ignore vars with no name or type if they have a AttrSpecification
    
    Backport of master CL https://golang.org/cl/17151.
    
    Fixes https://gcc.gnu.org/PR/68072.
    
    Reviewed-on: https://go-review.googlesource.com/17152

From-SVN: r230685

gcc/go/gofrontend/MERGE

-d52835c9376985f92f35c32af5f1808239981536
+128d5b14b8ab967cb61c01a9b2c596bda7d04c63
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/cmd/cgo/gcc.go

@@ -490,6 +490,11 @@ func (p *Package) loadDWARF(f *File, names []*Name) {
 			name, _ := e.Val(dwarf.AttrName).(string)
 			typOff, _ := e.Val(dwarf.AttrType).(dwarf.Offset)
 			if name == "" || typOff == 0 {
+				if e.Val(dwarf.AttrSpecification) != nil {
+					// Since we are reading all the DWARF,
+					// assume we will see the variable elsewhere.
+					break
+				}
 				fatalf("malformed DWARF TagVariable entry")
 			}
 			if !strings.HasPrefix(name, "__cgo__") {