[compiler-rt] [llvm] [PGO] Add option to always instrumenting loop entries (PR #116789)

[via llvm-commits]

ronryvchin wrote:

@ellishg Do you know how `llvm-project/llvm/test/tools/llvm-profdata/Inputs/function-entry-coverage.profdata` was generated?
The new bit broke `llvm-project/llvm/test/tools/llvm-profdata/show-covered.test` so I need to re-generate its input, but I cannot find the generation logic.
It was added in https://github.com/llvm/llvm-project/commit/11d3074267324e811ade248a991564fa6722754e

https://github.com/llvm/llvm-project/pull/116789