uclibc-ng has gettid()

--- xbmc-22.0b1-Piers.orig/xbmc/platform/linux/threads/ThreadImplLinux.cpp	2026-06-21 09:53:12.000000000 +0200
+++ xbmc-22.0b1-Piers/xbmc/platform/linux/threads/ThreadImplLinux.cpp	2026-07-26 01:19:27.442381623 +0200
@@ -18,12 +18,6 @@
 #include <sys/resource.h>
 #include <unistd.h>
 
-#if !defined(TARGET_ANDROID) && (defined(__GLIBC__) || defined(__UCLIBC__))
-#if defined(__UCLIBC__) || !__GLIBC_PREREQ(2, 30)
-#include <sys/syscall.h>
-#endif
-#endif
-
 namespace
 {
 
@@ -52,15 +46,6 @@ constexpr int ThreadPriorityToNativePrio
   }
 }
 
-#if !defined(TARGET_ANDROID) && (defined(__GLIBC__) || defined(__UCLIBC__))
-#if defined(__UCLIBC__) || !__GLIBC_PREREQ(2, 30)
-static pid_t gettid()
-{
-  return syscall(__NR_gettid);
-}
-#endif
-#endif
-
 std::once_flag flag;
 
 } // namespace
