[NFCI]Add SampleRecord::serialize and LineLocation::serialize to simplify FunctionSamples serialization#141669

mingmingl-llvm merged 2 commits intomainllvm/llvm-project:mainfrom

users/mingmingl-llvm/sprof-serialize-minillvm/llvm-project:users/mingmingl-llvm/sprof-serialize-miniCopy head branch name to clipboard