fix possible compilation error of vasnprintf.c

[Bruno Haible]

Without this patch, the DECL_LONG_DOUBLE_ROUNDING macro could be used without
being defined, leading to a compilation error.

2007-06-05  Bruno Haible  <address@hidden>

        * lib/vasnprintf.c [NEED_PRINTF_LONG_DOUBLE ||
        NEED_PRINTF_INFINITE_LONG_DOUBLE]: Include fpucw.h.

*** lib/vasnprintf.c    22 May 2007 01:07:46 -0000      1.52
--- lib/vasnprintf.c    6 Jun 2007 01:05:21 -0000
***************
*** 56,61 ****
--- 56,62 ----
  #if NEED_PRINTF_LONG_DOUBLE && !defined IN_LIBINTL
  # include <math.h>
  # include "float+.h"
+ # include "fpucw.h"
  #endif
  
  #if NEED_PRINTF_INFINITE_DOUBLE && !defined IN_LIBINTL
***************
*** 66,71 ****
--- 67,73 ----
  #if NEED_PRINTF_INFINITE_LONG_DOUBLE && !defined IN_LIBINTL
  # include <math.h>
  # include "isnanl-nolibm.h"
+ # include "fpucw.h"
  #endif
  
  #if NEED_PRINTF_DIRECTIVE_A && !defined IN_LIBINTL