cmd/internal/ld: fix symbol visibility for external linking

The original C code is: (x->type & SHIDDEN) ? 2 : 0, however when
cleaning up the code for c2go, the ternary operator is rewritten in
the exact opposite way.

We need a test for this, and that's being tracked as #10070.

Fixes #10067.

Change-Id: I24a5e021597d8bc44218c6e75bab6446513b76cf
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/6730Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/internal/ld/symtab.go

@@ -141,9 +141,9 @@ func putelfsym(x *LSym, s string, t int, addr int64, size int64, ver int, go_ *L
 	if Linkmode == LinkExternal {
 		addr -= int64((xo.Sect.(*Section)).Vaddr)
 	}
-	other := 2
+	other := STV_DEFAULT
 	if x.Type&SHIDDEN != 0 {
-		other = 0
+		other = STV_HIDDEN
 	}
 	putelfsyment(off, addr, size, bind<<4|type_&0xf, ((xo.Sect.(*Section)).Elfsect.(*ElfShdr)).shnum, other)
 	x.Elfsym = int32(numelfsym)