codegendecl on a const

[timothee]

`codegenDecl` is under-specified and should be improved

in meantime this works, however ugly: 
    
    
    when defined case2:
      from strutils import escape
      let myFile2 {.importc, nodecl.}: cstring
      {.emit: [""" __attribute__((section("DATA,.myFile"))) const char* myFile2 
= """, staticRead("/tmp/z02.txt").escape.static  , ";" ].}
      echo myFile2
    
    
    Run