No code generated for defaults when complex constants are referenced

The assignment of more complex constants looks like not fully implemented. Here's a test case:

struct thing {
  1: i32 hello,
  2: i32 goodbye
}

const map<i32,thing> GEN_WHAT = { 35 : { 'hello' : 325, 'goodbye' : 325352 } }

struct Foo {
  1:  map<i32,thing> complex = GEN_WHAT
}

service Bar {
  void Baz( 4: map<i32,thing> complex = GEN_WHAT)
}

At least for the languages I tested (C++, C# and Delphi) there is no code generated to assign the GEN_WHAT constant at all, altough it is used at two places in the IDL. I have not checked all the other languages, but there are very likely some more candidates around. The problem can be solved by testing against CV_IDENTIFIER and proper treatment of that special case in all of the affected places.

Remarks:

• Regarding the service args, there's a general problem for which another ticket exists: THRIFT-2315.
• I already fixed the HTML compiler with THRIFT-2370.