[llvm] [llvm-profdata] Emit error when counter value is greater than 2^56. (PR #69513)

[Zequan Wu via llvm-commits]

ZequanWu wrote:

> It seems the current version doesn't error out, but just emits a warning. I thought what we want is to make this a hard error by default, with a flag that makes it possible to treat it as a warning instead.

I see this error as a less fatal error compared to other existing errors, which just prints warning without fail llvm-profdata, like counter overflow, etc. Example at llvm/test/tools/llvm-profdata/overflow-instr.test. If we don't treat it as a hard error, it makes less sense to make large counter values an hard error.

https://github.com/llvm/llvm-project/pull/69513