[llvm] [SampleProfile] Support Eytzinger layout in SecNameTable (PR #211027)

[David Li via llvm-commits]

================
@@ -402,11 +408,91 @@ std::error_code SampleProfileWriterExtBinaryBase::writeNameTableSection(
     }
   }
 
+  if (UseMD5 && WriteEytzingerNameTables) {
+    if (auto EC = writeEytzingerNameTableSection(ProfileMap))
+      return EC;
+    return sampleprof_error::success;
+  }
+
   if (auto EC = writeNameTable())
     return EC;
   return sampleprof_error::success;
 }
 
+namespace {
+
+class EytzingerNameTable {
----------------
david-xl wrote:

Describe the table layout as comments (is there afdo  format documentation that needs to be updated?)

https://github.com/llvm/llvm-project/pull/211027