[llvm-objdump][AVR] Detect AVR architecture from ELF flags for disassembling (#174731)
This PR updates llvm-objdump to detect the specific AVR architecture
from the ELF header flags when no specific CPU is provided.
Fixes: #146451
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Signed-off-by: RuoyuQiu <cabbaken@outlook.com>
Signed-off-by: Ruoyu Qiu <cabbaken@outlook.com>
Co-authored-by: qiuruoyu <qiuruoyu@hygon.cn>