torque: workaround stod() limitations on Solaris

std::stod() on Solaris does not currently handle hex strings.
This commit provides a workaround based on strtol() until proper
stod() support is available.

This was encountered while updating Node.js to V8 8.8. For more
details see the following comment:

https://github.com/nodejs/node/pull/36139#issuecomment-740131942

Change-Id: I16ed80a817f6d9105e7153b10824b1fee8520432
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2692746Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73255}

src/torque/torque-parser.cc

@@ -1834,7 +1834,18 @@ base::Optional<ParseResult> MakeNumberLiteralExpression(
   // Meanwhile, we type it as constexpr float64 when out of int32 range.
   double value = 0;
   try {
+#if defined(V8_OS_SOLARIS)
+    // stod() on Solaris does not currently support hex strings. Use strtol()
+    // specifically for hex literals until stod() support is available.
+    if (number.find("0x") == std::string::npos &&
+        number.find("0X") == std::string::npos) {
+      value = std::stod(number);
+    } else {
+      value = static_cast<double>(strtol(number.c_str(), nullptr, 0));
+    }
+#else
     value = std::stod(number);
+#endif  // !defined(V8_OS_SOLARIS)
   } catch (const std::out_of_range&) {
     Error("double literal out-of-range").Throw();
   }