[llvm] [ctx_prof] Add support for ICP (PR #105469)

[Snehasish Kumar via llvm-commits]

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@@ -57,9 +57,23 @@ class PGOCtxProfContext final {
 
   GlobalValue::GUID guid() const { return GUID; }
   const SmallVectorImpl<uint64_t> &counters() const { return Counters; }
+  SmallVectorImpl<uint64_t> &counters() { return Counters; }
+
+  uint64_t getEntrycount() const { return Counters[0]; }
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snehasish wrote:

Do we need to assert that `!Counter.empty()`?

https://github.com/llvm/llvm-project/pull/105469