[llvm] [Support] Add decodeULEB128AndInc/decodeSLEB128AndInc (PR #85739)

[David Blaikie via llvm-commits]

dwblaikie wrote:

The lack of error handling and bounds checking in these versions seems a bit problematic? (like, I'm not sure they can be used safely/correctly?)

https://github.com/llvm/llvm-project/pull/85739