Allow calling of C++ methods from python

Currently it's not possible to call C++ methods from python.
Using this example:
```
class B
{
  static int static_func ();
  int arg0_func ();
  int arg1_func (int arg1);
  int arg2_func (int arg1, int arg2);
};

B *b_obj = new B;
```

Trying to call B::static_func gives this error:
```
(gdb) py b_obj = gdb.parse_and_eval('b_obj')
(gdb) py print(b_obj['static_func']())
Traceback (most recent call last):
  File "<string>", line 1, in <module>
RuntimeError: Value is not callable (not TYPE_CODE_FUNC).
Error while executing Python code.
```

TYPE_CODE_METHOD was simply missing as a possible type in
valpy_call, now the same is possible:
```
(gdb) py b_obj = gdb.parse_and_eval('b_obj')
(gdb) py print(b_obj['static_func']())
1111
```

Note that it's necessary to explicitely add the this pointer
as the first argument in a call of non-static methods:
```
(gdb) py print(b_obj['arg0_func']())
Traceback (most recent call last):
  File "<string>", line 1, in <module>
gdb.error: Too few arguments in function call.
Error while executing Python code.
(gdb) py print(b_obj['arg0_func'](b_obj))
198
```

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=13326
Approved-By: Tom Tromey <tom@tromey.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/gdb/python/py-value.c b/gdb/python/py-value.c
index 151b880..89ca098 100644
--- a/gdb/python/py-value.c
+++ b/gdb/python/py-value.c
@@ -1214,10 +1214,11 @@ valpy_call (PyObject *self, PyObject *args, PyObject *keywords)
       GDB_PY_HANDLE_EXCEPTION (except);
     }
 
-  if (ftype->code () != TYPE_CODE_FUNC)
+  if (ftype->code () != TYPE_CODE_FUNC && ftype->code () != TYPE_CODE_METHOD)
     {
       PyErr_SetString (PyExc_RuntimeError,
-		       _("Value is not callable (not TYPE_CODE_FUNC)."));
+		       _("Value is not callable (not TYPE_CODE_FUNC"
+			 " or TYPE_CODE_METHOD)."));
       return NULL;
     }