winapi_test chokes on TITLEBARINFO

[Francois Gouget]

When I run ./tools/winapi/winapi_test it chokes on the TITLEBARINFO
declaration in winuser.h:

typedef struct tagTITLEBARINFO {
    DWORD cbSize;
    RECT  rcTitleBar;
    DWORD rgstate[CCHILDREN_TITLEBAR+1];
} TITLEBARINFO, *PTITLEBARINFO, *LPTITLEBARINFO;

include/winuser.h: DWORD[CCHILDREN_TITLEBAR+1]: can't parse type
('DWORD') ('CCHILDREN_TITLEBAR+1')
Can't use string ("4") as a SCALAR ref while "strict refs" in use at
tools/winapi/c_type.pm line 283.

I believe this is because it does not know how to compute the value of
'CCHILDREN_TITLEBAR+1'. Though I'm not sure the second error is really
related to the first one.

I had a look but I'm pretty lost in the winapi code. Does anyone know
how to fix this problem?