[fix](be-ut)(clang-build)(aarch64) Fix the BRPC "sched_to itself" error when running BE UT

thirdparty/download-thirdparty.sh

@@ -373,7 +373,12 @@ echo "Finished patching ${AWS_SDK_SOURCE}"
 
 cd "${TP_SOURCE_DIR}/${BRPC_SOURCE}"
 if [[ ! -f "${PATCHED_MARK}" ]]; then
-    for file in "${TP_PATCH_DIR}"/brpc-1.2.0-*.patch; do
+    # Currently, there are two types of patches for BRPC in Doris:
+    # 1. brpc-fix-*.patch - These patches are not included in upstream but they can fix some bugs in some specific
+    #    scenarios.
+    # 2. brpc-{VERSION}-*.patch - These patches are included in upstream but they are not in current VERISON. We
+    #    backport some bug fixes to the current VERSION.
+    for file in "${TP_PATCH_DIR}"/brpc-*.patch; do
         patch -p1 <"${file}"
     done
     touch "${PATCHED_MARK}"

thirdparty/patches/brpc-fix-linux-aarch64-clang-build.patch

@@ -0,0 +1,24 @@
+diff --git a/src/bthread/task_group.cpp b/src/bthread/task_group.cpp
+index b8ead163..94ce5eb7 100644
+--- a/src/bthread/task_group.cpp
++++ b/src/bthread/task_group.cpp
+@@ -248,6 +248,9 @@ int TaskGroup::init(size_t runqueue_capacity) {
+     return 0;
+ }
+
++#if defined(__linux__) && defined(__aarch64__) && defined(__clang__)
++    __attribute__((optnone))
++#endif
+ void TaskGroup::task_runner(intptr_t skip_remained) {
+     // NOTE: tls_task_group is volatile since tasks are moved around
+     //       different groups.
+@@ -567,6 +570,9 @@ void TaskGroup::sched(TaskGroup** pg) {
+     sched_to(pg, next_tid);
+ }
+
++#if defined(__linux__) && defined(__aarch64__) && defined(__clang__)
++    __attribute__((optnone))
++#endif
+ void TaskGroup::sched_to(TaskGroup** pg, TaskMeta* next_meta) {
+     TaskGroup* g = *pg;
+ #ifndef NDEBUG