[interp] Always init locals (#32193)
Storing uninitialized locals in a managed object shouldn't crash the runtime, so they should be zeroed. This doesn't seem to regress performance on wasm since the initlocals flag is always set, currently. We should be able to remove it most of the time, once we add some multi basic block support to the cprop phase. This will enable us to further reduce call overhead.
Fixes https://github.com/mono/mono/issues/18527
Co-authored-by: Vlad Brezae <brezaevlad@gmail.com>