[clang] [dataflow] Parse formulas from text (PR #66424)

[Yitzhak Mandelbaum via cfe-commits]

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@@ -87,6 +87,9 @@ class alignas(const Formula *) Formula {
                          ArrayRef<const Formula *> Operands,
                          unsigned Value = 0);
 
+  // Parse Formulas using Arena rather than caling this function directly.
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ymand wrote:

nit: Maybe prefix with "note:" or somesuch? I started reading this as a description of the function.

https://github.com/llvm/llvm-project/pull/66424