deal with some win/win32 warnings

win/win32/mhdlg.c(137)   : warning C4456: declaration of 'wbuf' hides
                           previous local declaration
win/win32/mhdlg.c(62)    : note: see declaration of 'wbuf'
win/win32/mhdlg.c(875)   : warning C4189: 'gender': local variable is
                           initialized but not referenced
win/win32/mhdlg.c(874)   : warning C4189: 'race': local variable is
                           initialized but not referenced
win/win32/mhdlg.c(876)   : warning C4189: 'alignment': local variable is
                           initialized but not referenced
win/win32/mhdlg.c(873)   : warning C4189: 'role': local variable is
                           initialized but not referenced
win/win32/mhinput.h(24)  : warning C4201: nonstandard extension used:
                           nameless struct/union
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/mhinput.h(24)  : warning C4201: nonstandard extension used:
                           nameless struct/union
win/win32/mhinput.h(24)  : warning C4201: nonstandard extension used:
                           nameless struct/union
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/mhmenu.c(62)   : warning C4201: nonstandard extension used:
                           nameless struct/union
win/win32/mhmenu.c(1082) : warning C4456: declaration of 'monitorScale'
                           hides previous local declaration
win/win32/mhmenu.c(995)  : note: see declaration of 'monitorScale'
win/win32/mhmenu.c(1142) : warning C4456: declaration of 'wbuf' hides
                           previous local declaration
win/win32/mhmenu.c(986)  : note: see declaration of 'wbuf'
win/win32/mhmenu.c(1082) : warning C4189: 'monitorScale': local variable
                           is initialized but not referenced
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/mhmsgwnd.c(700): warning C4701: potentially uninitialized
                           local variable 'size' used
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/mhsplash.c(158): warning C4189: 'verstrsize': local variable
                           is initialized but not referenced
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/mhstatus.c(353): warning C4057: 'function':
                           'const unsigned char *' differs in indirection
                           to slightly different base types from 'const char *'
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/mhmsg.h(70)    : warning C4200: nonstandard extension used:
                           zero-sized array in struct/union
win/win32/NetHackW.c(181): warning C4456: declaration of 'buf' hides
                           previous local declaration
win/win32/NetHackW.c(90) : note: see declaration of 'buf'
win/win32/NetHackW.c(189): warning C4456: declaration of 'buf' hides
                           previous local declaration
win/win32/NetHackW.c(90) : note: see declaration of 'buf'

win/win32/mhmain.c

@@ -1248,7 +1248,6 @@ mswin_apply_window_style_all(void)
 }
 
 // returns strdup() created pointer - callee assumes the ownership
-#define TEXT_BUFFER_SIZE 4096
 char *
 nh_compose_ascii_screenshot(void)
 {