range-op-float: Remove inappropriate frange_drop_infs call [PR126549]

For integer to floating conversions I've added frange_drop_infs
call into the handler.  Supposedly I thought that integers converted
to floating point are never +-inf, but that is clearly not the case
as the testcases show.  For _Float16 it can be +-inf very easily,
as the finite range is just [-65504.0f16,65504.0f16], for others
all one needs is a large enough _BitInt.

The following patch just drops that call.  In the common cases,
+-inf will not appear in the range anyway, lb and ub will be usually
finite.

2026-08-04  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/126549
	* range-op-float.cc (operator_cast::fold_range): Don't call
	frange_drop_infs.

	* gcc.dg/torture/pr126549.c: New test.
	* gcc.dg/torture/bitint-107.c: New test.

Reviewed-by: Aldy Hernandez <aldy@quesejoda.com>