revert HLSLHalf_t constructor diff

Author: V-FEXrt

tools/clang/unittests/HLSLExec/HlslTestDataTypes.h

@@ -113,17 +113,16 @@ struct HLSLHalf_t {
     Val = DirectX::PackedVector::XMConvertFloatToHalf(F);
   }
   HLSLHalf_t(const double D) {
-    float F = 0.5;
-    if (D >= std::numeric_limits<float>::max())
+    float F;
+    if (D >= std::numeric_limits<double>::max())
       F = std::numeric_limits<float>::max();
-    else if (D <= std::numeric_limits<float>::lowest())
+    else if (D <= std::numeric_limits<double>::lowest())
       F = std::numeric_limits<float>::lowest();
     else
       F = static_cast<float>(D);
 
     Val = DirectX::PackedVector::XMConvertFloatToHalf(F);
   }
-
   HLSLHalf_t(const uint32_t U) {
     float F = static_cast<float>(U);
     Val = DirectX::PackedVector::XMConvertFloatToHalf(F);