[SYCL] Fix std::exp(complex<double>) edge case on Windows (#15489)

This is a follow-up for #15162

There are no new tests added with this PR, because we already have this
edge case covered by existing tests here:


https://github.com/intel/llvm/blob/3e98b3a09254863423f82d10aa7d40a8b64dbdd3/sycl/test-e2e/DeviceLib/std_complex_math_fp64_test.cpp#L202

But we don't have a Windows machine with a GPU which supports `fp64` and
therefoere this edge case went unnoticed by our CI. The change was
locally tested in the right environment.

Patch-By: Justin Cai <justin.cai@intel.com>

Author: AlexeySachkov

libdevice/cmath_wrapper_fp64.cpp

@@ -395,7 +395,7 @@ short _Exp(double *px, double y,
   if (*px < -HUGE_EXP || y == 0.0) // certain underflow
     *px = 0.0;
   else if (HUGE_EXP < *px) { // certain overflow
-    *px = _Inf._Double;
+    *px = _Inf._Double * (y < 0.F ? -1.F : 1.F);
     ret = _INFCODE;
   } else { // xexp won't overflow
     double g = *px * invln2;