const field initialization with namespaced value results in 'Blank identifier error' while using ast2
d875252

```c++
// smallest-failing-example.h
enum fa { il };
struct fails { static constexpr fa fail0 = fa::il; };
```

```sh
toast -p smallest-failing-example.h -m cpp -n -f ast2 -d
```

```
# Generated @ 2020-05-30T13:00:04-07:00
# Command line:
#   /Volumes/origin/ws/_wrk/var/cache/nimble/pkgs/nimterop-0.5.7/nimterop/toast -p smallest-failing-example.h -m cpp -n -f ast2 -d

import nimterop/types

{.push hint[ConvFromXtoItselfNotNeeded]: off.}


# addEnum()

# Input => enum fa { il }

# (enum_specifier 2 1 14
#  (type_identifier 2 6 2 "fa")
#  (enumerator_list 2 9 6
#   (enumerator 2 11 2 "il"
#    (identifier 2 11 2 "il")
#   )
#  )
# )

# addType()

# Input => struct fails { static constexpr fa fail0 = fa::il; }

# (struct_specifier 3 1 52
#  (type_identifier 3 8 5 "fails")
#  (field_declaration_list 3 14 39
#   (field_declaration 3 16 35
#    (storage_class_specifier 3 16 6 "static")
#    (type_qualifier 3 23 9 "constexpr")
#    (type_identifier 3 33 2 "fa")
#    (field_identifier 3 36 5 "fail0")
#    (scoped_identifier 3 44 6 "fa::il"
#     (namespace_identifier 3 44 2 "fa")
#     (identifier 3 48 2 "il")
#    )
#   )
#  )
# )

# addType(): case 1

# addTypeObject()
toast.nim(232)           toast
cligen.nim(733)          cligenDoNotCollideWithGlobalVar
cligen.nim(651)          dispatchmain
toast.nim(151)           main
toast.nim(23)            process
ast2.nim(1854)           parseNim
ast2.nim(1759)           searchTree
ast2.nim(1736)           processNode
ast2.nim(1212)           addType
ast2.nim(835)            addTypeObject
ast2.nim(729)            newRecListTree
ast2.nim(504)            newIdentDef
comphelp.nim(94)         getNameInfo
getters.nim(149)         getIdentifier
assertions.nim(29)       failedAssertImpl
assertions.nim(22)       raiseAssert
fatal.nim(49)            sysFatal
Error: unhandled exception: getters.nim(149, 12) `name.nBl` Blank identifier error [AssertionDefect]
```

```c++
// test.h
// just trying to understand
const int succeed = 0;
struct yup { static constexpr char ahuh = '!'; };
const yup yupyup = {};
enum fa { il };
namespace fail { const int again = 1; }

static constexpr fa doesnt = fa::il;

struct succeeds {
  static constexpr int success0 = ::succeed;
  static constexpr char success1 = yupyup.ahuh;
};

struct fails {
  static constexpr fa fail0 = ::fa::il;
  static constexpr int fail1 = fail::again;
};
```