swift

c957f33a - Adjust to "[IRBuilder] Deprecate overloads with redundant BB argument (#229102)"

Adjust to "[IRBuilder] Deprecate overloads with redundant BB argument (#229102)" The `SetInsertPoint(BasicBlock *, BasicBlock::iterator)` overload and the matching `IRBuilder` constructors are now deprecated because the block is derivable from the iterator. Switch all IRGen callers to the iterator-only overload, and change the `SetInsertPoint` and `SavedInsertionPointRAII` overloads of our `IRBuilder` wrapper to take just an iterator, mirroring upstream. This is behavior-preserving: the deprecated overload already forwarded to the iterator-only one. See https://github.com/llvm/llvm-project/commit/bb0020c308867388b5255fc1095fd073b21a873e (https://github.com/llvm/llvm-project/pull/229102).