Problem compiling with <iostream.h>

[John Pfuntner <John_Pfuntner at tivoli dot com>]

I built gcc 2.95.1 on HP-UX 11.00 last week and I thought it was working
fine but this morning, I can't get it to compile a simple C++ program
that includes <iostream.h>:

    /tmp> cat hello++.cpp
    #include <iostream.h>
    main() {
      cout << "Hello, gnu++ world\n";
    }
    /tmp> g++ -o hello++ hello++.cpp
    In file included from
/usr/local/lib/gcc-lib/hppa2.0n-hp-hpux11.00/2.95.1/../../../../include/g++-3/streambuf.h:36,

                     from
/usr/local/lib/gcc-lib/hppa2.0n-hp-hpux11.00/2.95.1/../../../../include/g++-3/iostream.h:31,

                     from hello++.cpp:1:

/usr/local/lib/gcc-lib/hppa2.0n-hp-hpux11.00/2.95.1/../../../../include/g++-3/libio.h:30:
_G_config.h: No such file or directory

I found _G_config.h in
/usr/local/gcc-2.95.1/hppa2.0n-hp-hpux11.00/libio/.  Is that where it's
supposed to be?  How is gcc supposed to find it?

I'm almost positive this same program compiled fine last week.  What am
I doing wrong????????