[compiler-rt] [llvm] [TypeProf][InstrFDO]Omit vtable symbols in indexed profiles by default (PR #96520)

[Mingming Liu via llvm-commits]

minglotus-6 wrote:

>  Let me know if there is a scenario or example we'd prefer to override the option in separate changes!

I'm going to land this change with `--keep-vtable-symbols=false` after the following tests

With prior released `llvm-profdata` as `cli1`, `llvm-profdata` built with this PR as `cli2`.
* Use`cli2` to generated profiles and use `cli1` to consume (merge, show, overlap) them.
* Use `cli1` to generate profiles and use `cli2` to consume them.

Both ways things work. 

https://github.com/llvm/llvm-project/pull/96520