[llvm] InstProfiling: Give the name to profc_bias. NFC. (PR #95587)

[NAKAMURA Takumi via llvm-commits]

chapuni wrote:

@ellishg At the moment, I've made this dedicated to "profc_bias".

I'm afraid that "profc_bias" would confuse since it is similar to other "profc" structure. I will introduce "bias value for bitmap" as "profbm_bias" later.

I will create another request for "profc_addr" and "pgocount" later.

https://github.com/llvm/llvm-project/pull/95587