#88 PERLUD_DECLARE

[Jean-Damien Durand]

Compiling Win32-GUI-1.14 with cl from Visual Studio 2014, I came across a case where PERLUD_DECLARE can be defined to nothing, leaving to a statement that cl compiler dislike, i.e.:

typedef struct tagPERLWIN32GUI_USERDATA {
    DWORD       dwSize;                                                 // struct size (our signature)
    ;                                                     // a pointer to the Perl Object
    SV*         svSelf;                                                 // a pointer to ourself
    etc

A proposed patch is attached.