In ExpandFPLibCall, an assumption is made that all floating point
libcalls that take integer arguments use unsigned integers. In the case
of ldexp and frexp, this assumption is incorrect, leading to
miscompilation and subsequent target-dependent incorrect operation.
Indicate that ldexp and frexp utilize signed arguments in
ExpandFPLibCall.
Fixes#108904
Signed-off-by: Timothy Pearson <tpearson@solidsilicon.com>
