Revert "ieee-fp: remove _fpreset from si_trap_fpe"

This reverts commit bd9c590810.
Apparently, _fpreset is not just equivalent to feclearexcept and really
needed when doing a longjmp out of a signal handler. On top of that, with
MSVC 2019, I now observe segmentation faults without _fpreset, but not with
_fpreset in si_trap_fpe!

src/c/unixint.d

@@ -1236,6 +1236,9 @@ si_trap_fpe(cl_object condition, cl_object flag)
 # ifdef HAVE_FENV_H
         feclearexcept(all);
 # endif
+# if defined(ECL_MS_WINDOWS_HOST)
+        _fpreset();
+# endif
 # ifdef HAVE_FEENABLEEXCEPT
         fedisableexcept(all & ~bits);
         feenableexcept(all & bits);