The 'mode' argument to __vfscanf_internal allows the selection of the
long double format for all long double arguments requested by the format
string. Currently, there are two possibilities: long double with the
same format as double or long double as something else. The 'something
else' format varies between architectures, and on powerpc64le, it means
IBM Extended Precision format.
In preparation for the third option of long double format on
powerpc64le, this patch uses the new mode mask,
SCANF_LDBL_USES_FLOAT128, which tells __vfscanf_internal to call
__strtof128_internal, instead of __strtold_internal, and save the output
into a _Float128 variable.
Tested for powerpc64le.
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>
