[clang] [llvm] [IR] Do not store Function inside BlockAddress (PR #137958)

[Matt Arsenault via cfe-commits]

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@@ -912,6 +912,11 @@ class BlockAddress final : public Constant {
   /// block must be embedded into a function.
   static BlockAddress *get(BasicBlock *BB);
 
+  /// Return a BlockAddress for the specified basic block, which may not be
+  /// part of a function. The specified type must match the type of the function
+  /// the block will be inserted into.
+  static BlockAddress *get(Type *Ty, BasicBlock *BB);
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arsenm wrote:

I think block address should be explicitly disallowed for unparented blocks 

https://github.com/llvm/llvm-project/pull/137958