[Fuchsia] Enable CPU profiling for the standalone VM

runtime/vm/os_thread_fuchsia.cc

Index: runtime/vm/os_thread_fuchsia.cc
diff --git a/runtime/vm/os_thread_fuchsia.cc b/runtime/vm/os_thread_fuchsia.cc
index e4f7bba30285eae91162ff3bf20560d0a9e776f2..5b236b9a6be5a5f0a3663c7ff0f3c23ba3286d7f 100644
--- a/runtime/vm/os_thread_fuchsia.cc
+++ b/runtime/vm/os_thread_fuchsia.cc
@@ -5,10 +5,12 @@
 #include "platform/globals.h"  // NOLINT
 #if defined(HOST_OS_FUCHSIA)
 
+#include "vm/os.h"
 #include "vm/os_thread.h"
 #include "vm/os_thread_fuchsia.h"
 
 #include <errno.h>  // NOLINT
+#include <magenta/status.h>
 #include <magenta/syscalls.h>
 #include <magenta/syscalls/object.h>
 #include <magenta/threads.h>
@@ -163,7 +165,10 @@ ThreadId OSThread::GetCurrentThreadId() {
   mx_status_t status =
       mx_object_get_info(thread_handle, MX_INFO_HANDLE_BASIC, &info,
                          sizeof(info), nullptr, nullptr);
-  return status == NO_ERROR ? info.koid : MX_KOID_INVALID;
+  if (status != NO_ERROR) {
+    FATAL1("Failed to get thread koid: %s\n", mx_status_get_string(status));
+  }
+  return info.koid;
 }
 
 
@@ -398,7 +403,12 @@ Monitor::WaitResult Monitor::WaitMicros(int64_t micros) {
   Monitor::WaitResult retval = kNotified;
   if (micros == kNoTimeout) {
     // Wait forever.
-    int result = pthread_cond_wait(data_.cond(), data_.mutex());
+    int result;
+    do {
+      result = pthread_cond_wait(data_.cond(), data_.mutex());
+      // TODO(MG-795): Disallow ETIMEDOUT when pthread_cond_wait() can no longer
+      // return it.
+    } while (result == ETIMEDOUT);
     VALIDATE_PTHREAD_RESULT(result);
   } else {
     struct timespec ts;