Merge GDB 7.5.1

gdb/testsuite/gdb.go/types.go

+package main
+
+import "fmt"
+
+// Self-referential type.
+type T *T
+
+// Mutually recursive types.
+type T1 *T2
+type T2 *T1
+
+// Mutually recursive struct types.
+type S1 struct { p_s2 *S2 }
+type S2 struct { p_s1 *S1 }
+
+func main () {
+  fmt.Println ("Shall we?")
+  var t T
+  fmt.Println (t)
+  var s1 S1
+  var s2 S2
+  fmt.Println (s1)
+  fmt.Println (s2)
+}