msvcrt: Use __scalbn helper in ldexp implementation.

dlls/msvcrt/math.c

@@ -3472,14 +3472,12 @@ int * CDECL __fpecode(void)
  */
 double CDECL ldexp(double num, int exp)
 {
-  double z = unix_funcs->ldexp(num,exp);
+  double z = __scalbn(num, exp);
 
   if (isfinite(num) && !isfinite(z))
     return math_error(_OVERFLOW, "ldexp", num, exp, z);
   if (num && isfinite(num) && !z)
     return math_error(_UNDERFLOW, "ldexp", num, exp, z);
-  if (z == 0 && signbit(z))
-    z = 0.0; /* Convert -0 -> +0 */
   return z;
 }
 

dlls/msvcrt/unixlib.c

@@ -139,14 +139,6 @@ static float CDECL unix_hypotf(float x, float y)
 }
 
 /*********************************************************************
- *      ldexp
- */
-static double CDECL unix_ldexp(double num, int exp)
-{
-    return ldexp( num, exp );
-}
-
-/*********************************************************************
  *      lgamma
  */
 static double CDECL unix_lgamma(double x)
@@ -306,7 +298,6 @@ static const struct unix_funcs funcs =
     unix_frexpf,
     unix_hypot,
     unix_hypotf,
-    unix_ldexp,
     unix_lgamma,
     unix_lgammaf,
     unix_log,

dlls/msvcrt/unixlib.h

@@ -33,7 +33,6 @@ struct unix_funcs
     float           (CDECL *frexpf)(float x, int *exp);
     double          (CDECL *hypot)(double x, double y);
     float           (CDECL *hypotf)(float x, float y);
-    double          (CDECL *ldexp)(double x, int exp);
     double          (CDECL *lgamma)(double x);
     float           (CDECL *lgammaf)(float x);
     double          (CDECL *log)(double x);