c0f5cc14ef9fae2b2de4222ee061729629ebb6b4 build: Fix `libmultiprocess` cross-compiling to Linux hosts (Hennadii Stepanov)
Pull request description:
To successfully call the [`capnp_generate_cpp()`](d576d975de/CMakeLists.txt (L45)) function, the `libmultiprocess` build system must be provided with paths to the native `capnp` and `capnpc-c++` tools.
This [comment](https://github.com/bitcoin/bitcoin/issues/24387#issuecomment-1054776195) points the same:
> I think `packages/libmultiprocess.mk` probably needs to be passing a `-DCAPNP_EXECUTABLE=.../depends/arm-linux-gnueabihf/native/bin/capnp` argument to cmake. Also the package should have dependencies on both `capnp` and `native_capnp`.
Fixesbitcoin/bitcoin#24387.
ACKs for top commit:
ryanofsky:
Code review ACK c0f5cc14ef9fae2b2de4222ee061729629ebb6b4
Tree-SHA512: 2986d8bf98d2761eceba21b1897145c5185a0922d4c2084e8812d4d07dc94237e5c2809036641c4f7c491a3414727fff328cba91ce138b89e37ec5cba61d8f61