Fix DoubleToInteger to never return -0

DoubleToInteger, which corresponds to the ToIntegerOrInfinity AO in
ecma262, never returns -0. Currently there's a bug as std::ceil can
return -0.

Bug: v8:10271
Change-Id: Id5e7d040ef9d186462022dc96052d7920be6ebed
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3869196
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82950}

src/numbers/conversions-inl.h

@@ -80,12 +80,12 @@ inline float DoubleToFloat32(double x) {
   return static_cast<float>(x);
 }
 
+// #sec-tointegerorinfinity
 inline double DoubleToInteger(double x) {
   if (std::isnan(x)) return 0;
   if (!std::isfinite(x)) return x;
-  // ToInteger normalizes -0 to +0.
-  if (x == 0.0) return 0;
-  return (x >= 0) ? std::floor(x) : std::ceil(x);
+  // ToIntegerOrInfinity normalizes -0 to +0, so add 0.0.
+  return ((x >= 0) ? std::floor(x) : std::ceil(x)) + 0.0;
 }
 
 // Implements most of https://tc39.github.io/ecma262/#sec-toint32.