libiberty: make install doesn't install obstack.h (mingw32)

[Phil Lello]

According to http://gcc.gnu.org/onlinedocs/libiberty/Using.html:
> Passing --enable-install-libiberty to the configure script when 
building |libiberty| causes the header files and archive library to be 
installed when make install is run

When I run make install against the current svn libiberty code, 
obstack.h doesn't get installed.

I'm cross-compiling for Win32 (via ./configure --host=i586-mingw32msvc 
--prefix=/usr/i586-mingw32msvc  --enable-install-libiberty), 
specifically because I want the obstack functionality missing on this 
platfrom.

Is the omission of obstack.h a mistake, or by design? If by design, what 
is the reason?

Thanks,

Phil