[llvm] [Coverage] MCDC: Move findIndependencePairs deferred into MCDCRecord (PR #121188)

[NAKAMURA Takumi via llvm-commits]

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@@ -507,7 +511,8 @@ struct MCDCRecord {
   /// via PosToID[].
   TVRowPair getConditionIndependencePair(unsigned Condition) {
     assert(isConditionIndependencePairCovered(Condition));
-    return IndependencePairs[PosToID[Condition]];
+    assert(IndependencePairs);
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chapuni wrote:

It's redundant since `isConditionIndependencePairCovered` checks `IndependencePairs`. That said, I want to reconfirm before its use `*IndependencePairs`.

https://github.com/llvm/llvm-project/pull/121188