[llvm] [memprof] Add computeUndriftMap (PR #116478)

[Kazu Hirata via llvm-commits]

================
@@ -298,4 +304,189 @@ attributes #2 = { builtin allocsize(0) }
   ASSERT_THAT(FooCallSites, SizeIs(1));
   EXPECT_THAT(FooCallSites[0], Pair(FieldsAre(1U, 10U), 0));
 }
+
+// Populate those fields returned by getHotColdSchema.
+MemInfoBlock makePartialMIB() {
+  MemInfoBlock MIB;
+  MIB.AllocCount = 1;
+  MIB.TotalSize = 5;
+  MIB.TotalLifetime = 10;
+  MIB.TotalLifetimeAccessDensity = 23;
+  return MIB;
+}
+
+IndexedMemProfRecord
+makeRecordV2(std::initializer_list<::llvm::memprof::CallStackId> AllocFrames,
+             std::initializer_list<::llvm::memprof::CallStackId> CallSiteFrames,
+             const MemInfoBlock &Block, const memprof::MemProfSchema &Schema) {
+  llvm::memprof::IndexedMemProfRecord MR;
+  for (const auto &CSId : AllocFrames)
----------------
kazutakahirata wrote:

Fixed in the latest iteration.

https://github.com/llvm/llvm-project/pull/116478