This patch focuses on the ARM64 general context handling code.
The modifications are aimed at enhancing performance by simplifying
context save/restore operations.
Changes include:
- Adjusted stack alignment in `arch_set_thread_context` function.
- Updated `lwp_gcc.S` to reset frame pointer and link register.
- Refined `rt_hw_backtrace_frame_unwind` to handle user space address checks.
- Added `GET_THREAD_SELF` macro in `asm-generic.h`.
- Simplified context saving/restoring in `context_gcc.h` and related files.
- Optimized `rt_hw_context_switch_interrupt` and related assembly routines.
Signed-off-by: Shell <smokewood@qq.com>