Merge bitcoin/bitcoin#31740: depends: Update libmultiprocess library before converting to subtree

4e0aa1835b test: Add test for IPC serialization bug (Ryan Ofsky)
2221c8814d depends: Update libmultiprocess library before converting to subtree (Ryan Ofsky)

Pull request description:

  This should be the final update to the libmultiprocess package via the depends system. It brings in the libmultiprocess cmake changes from https://github.com/chaincodelabs/libmultiprocess/pull/136 needed to support building as subtree. After this, followup PR #31741 will add libmultiprocess as a git subtree and depends will just use the git subtree instead of hardcoding its own version hash.

  Since there have been libmultiprocess API changes since the last update, this commit also updates bitcoin code to be compatible with them.

  This update has the following new changes since previous update #31105:

  https://github.com/chaincodelabs/libmultiprocess/pull/121 ProxyClientBase: avoid static_cast to partially constructed object
  https://github.com/chaincodelabs/libmultiprocess/pull/120 proxy-types.h: add static_assert to detect int/enum size mismatch
  https://github.com/chaincodelabs/libmultiprocess/pull/127 ProxyClientBase: avoid static_cast to partially destructed object
  https://github.com/chaincodelabs/libmultiprocess/pull/129 Fix "disconnected: write(m_post_fd, &buffer, 1): Broken pipe" EventLoop shutdown races.
  https://github.com/chaincodelabs/libmultiprocess/pull/130 refactor: Add CleanupRun function to dedup clean list code
  https://github.com/chaincodelabs/libmultiprocess/pull/131 doc: fix startAsyncThread comment
  https://github.com/chaincodelabs/libmultiprocess/pull/133 Fix debian "libatomic not found" error in downstream builds
  https://github.com/chaincodelabs/libmultiprocess/pull/94 c++ 20 cleanups
  https://github.com/chaincodelabs/libmultiprocess/pull/135 refactor: proxy-types.h API cleanup
  https://github.com/chaincodelabs/libmultiprocess/pull/136 cmake: Support being included with add_subdirectory
  https://github.com/chaincodelabs/libmultiprocess/pull/137 doc: Fix broken markdown links

ACKs for top commit:
  Sjors:
    ACK 4e0aa1835b
  vasild:
    ACK 4e0aa1835b
  TheCharlatan:
    ACK 4e0aa1835b

Tree-SHA512: 6d81cdf7f44762c7f476212295f6224054fd0a61315bb54786bc7758a2b33e5a2fce925c71e36f7bda320049aa14e7218a458ceb03dacbb869632c466c4789b0

src/test/ipc_test.capnp

@@ -20,4 +20,5 @@ interface FooInterface $Proxy.wrap("FooImplementation") {
     passTransaction @3 (arg :Data) -> (result :Data);
     passVectorChar @4 (arg :Data) -> (result :Data);
     passBlockState @5 (arg :Mining.BlockValidationState) -> (result :Mining.BlockValidationState);
+    passScript @6 (arg :Data) -> (result :Data);
 }

src/test/ipc_test.cpp

@@ -121,6 +121,10 @@ void IpcPipeTest()
     BOOST_CHECK_EQUAL(bs3.GetRejectReason(), bs4.GetRejectReason());
     BOOST_CHECK_EQUAL(bs3.GetDebugMessage(), bs4.GetDebugMessage());
 
+    auto script1{CScript() << OP_11};
+    auto script2{foo->passScript(script1)};
+    BOOST_CHECK_EQUAL(HexStr(script1), HexStr(script2));
+
     // Test cleanup: disconnect pipe and join thread
     disconnect_client();
     thread.join();

src/test/ipc_test.h

@@ -6,6 +6,7 @@
 #define BITCOIN_TEST_IPC_TEST_H
 
 #include <primitives/transaction.h>
+#include <script/script.h>
 #include <univalue.h>
 #include <util/fs.h>
 #include <validation.h>
@@ -19,6 +20,7 @@ public:
     CTransactionRef passTransaction(CTransactionRef t) { return t; }
     std::vector<char> passVectorChar(std::vector<char> v) { return v; }
     BlockValidationState passBlockState(BlockValidationState s) { return s; }
+    CScript passScript(CScript s) { return s; }
 };
 
 void IpcPipeTest();