[llvm] [NFC][StaticDataProfileInfo] Refactor StaticDataProfileInfo::getConstantSectionPrefix and extract analysis based on PGO-counter to be a helper function (PR #162388)

[Mingming Liu via llvm-commits]

mingmingl-llvm wrote:

Error from both [linux](https://github.com/llvm/llvm-project/actions/runs/18512578088/job/52756517645?pr=162388) and [windows](https://github.com/llvm/llvm-project/actions/runs/18512578088/job/52756517646?pr=162388) are around `clang/test/CodeGenHLSL/resources/StructuredBuffers-methods-lib.hlsl:29` and `clang/test/CodeGenHLSL/resources/StructuredBuffers-methods-ps.hlsl:26`, and are not related with this codegen change.

Will merge this change.

https://github.com/llvm/llvm-project/pull/162388