btwowc(EOF) hang with gcc 4.4.2

[Karl Berry]

Hi Jim and all,

On a CentOS 5.4 system, compiling with gcc 4.4.2, configure goes into an
infinite loop here:
checking whether btowc(EOF) is correct... 

Running gdb on conftest gets a backtrace like this:
#0  0x080491d1 in btowc (__c=-1) at /usr/include/wchar.h:331
#1  0x08049431 in btowc () at /usr/include/wchar.h:332
#2  main () at conftest.c:276

Where that line 331 is:
331     { return (__builtin_constant_p (__c) && __c >= '\0' && __c <= '\x7f'

This does not happen with other versions of gcc.  I can't tell if it's a
gcc bug or a system include file bug or something actually in coreutils,
but here's the report anyway.  It was pretty unsettling to have
configure hang.

k