[llvm-branch-commits] [llvm] [BOLT] Factor out MCInstReference from gadget scanner (NFC) (PR #138655)

[Anatoly Trosinenko via llvm-branch-commits]

atrosinenko wrote:

This is similar to `MCPlusBuilder::InstructionIterator` class, but not tied to some specific iteration semantics. In a subsequent PR I plan adding an `std::optional<MCInstReference> getSinglePredecessor()` function with an extra feature of handling the case of the first instruction in a basic block with exactly one predecessor (this is important to analyze pauth-specific `BR_JumpTable` lowering), but other flavors of `operator--` could be possible.

https://github.com/llvm/llvm-project/pull/138655