pythongh-112535: Update _Py_ThreadId() to support PowerPC

Author: corona10

Include/object.h

@@ -261,6 +261,12 @@ _Py_ThreadId(void)
     __asm__ ("mrs %0, tpidrro_el0" : "=r" (tid));
 #elif defined(__aarch64__)
     __asm__ ("mrs %0, tpidr_el0" : "=r" (tid));
+#elif defined(__powerpc64__)
+    register uintptr_t thread_pointer __asm__ ("r13");
+    tid = thread_pointer;
+#elif defined(__powerpc__)
+    register uintptr_t thread_pointer __asm__ ("r2");
+    tid = thread_pointer;
 #else
   # error "define _Py_ThreadId for this platform"
 #endif