Revert "Do schur_div with a direct 64 bit division instead of a loop on x86"

This reverts commit 923f3e95.

The optimized version differed from the original in a few cases
(in some cases where the return value turned out to be negative
while the original implementation returned a positive value),
so revert it for now until it has been analyzed completely.

libFDK/src/fixpoint_math.cpp

@@ -443,15 +443,6 @@ FIXP_DBL sqrtFixp(FIXP_DBL op)
 
 *****************************************************************************/
 
-#if defined(__x86__)
-FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count)
-{
-    INT64 tmp=(INT64)num<<31;
-    LONG div=(tmp/denum)>>(DFRACT_BITS-count);
-    return (FIXP_DBL)(div) << (DFRACT_BITS-count);
-}
-
-#else
 
 FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count)
 {
@@ -478,7 +469,6 @@ FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count)
     return (FIXP_DBL)(div << (DFRACT_BITS - count));
 }
 
-#endif
 
 #endif /* !defined(FUNCTION_schur_div) */