Do not rely on uniquiness of pthread_t

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 8e5e3536028219e8edca9d33e97cc0b7020a42d5..d8a465c1162a6c14cdf308edb949410b3577c148 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -10171,8 +10171,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetThreadDetails) {
     details->set(kThreadDetailsCurrentThreadIndex,
                  isolate->heap()->true_value());
     details->set(kThreadDetailsThreadIdIndex,
-                 Smi::FromInt(
-                     isolate->thread_manager()->CurrentId()));
+                 Smi::FromInt(ThreadId::Current().ToInteger()));
   } else {
     // Find the thread with the requested index.
     int n = 1;
@@ -10189,7 +10188,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetThreadDetails) {
     // Fill the details.
     details->set(kThreadDetailsCurrentThreadIndex,
                  isolate->heap()->false_value());
-    details->set(kThreadDetailsThreadIdIndex, Smi::FromInt(thread->id()));
+    details->set(kThreadDetailsThreadIdIndex,
+                 Smi::FromInt(thread->id().ToInteger()));
   }
 
   // Convert to JS array and return.