[llvm] [PGO] Ensure non-zero entry-count after `populateCounters` (PR #112029)

[Ellis Hoag via llvm-commits]

================
@@ -0,0 +1,28 @@
+; RUN: llvm-profdata merge %S/Inputs/fix_entry_count_sampled.proftext -o %t.profdata
+; RUN: opt < %s -passes=pgo-instr-use -pgo-test-profile-file=%t.profdata -S | FileCheck %s --check-prefix=USE
----------------
ellishg wrote:

Since this is the only `FileCheck` command, can we use the default check prefix?

https://github.com/llvm/llvm-project/pull/112029