[llvm] [BOLT][merge-fdata]Fix support for fdata files starting with no_lbr on ARM platform (PR #112328)

[via llvm-commits]

zrxxzz wrote:

Through testing, it has been proven that even without LBR, merging samples on the ARM platform still achieves good results for MySQL. 
Whether based on the standard version or the PGO-optimized version, the baseline version sees an improvement of around 10%, and the PGO version sees an improvement of around 5%.

https://github.com/llvm/llvm-project/pull/112328