[1.0 -> main] Don't use deduced return type in test contract as it fails in template instantation

[greg7mdp]

Partially resolves #677.

This resolves the first issue:

/home/greg/github/enf/cdt/build_clang18_debug/bin/../include/eosiolib/contracts/eosio/multi_index.hpp:442:96: error: function 'primary_key' with deduced return type cannot be used before it is defined

Remaining issue

An issue remains with the use of the macro EOSIO_DISPATCH( eosiosystem::system_contract, ... in unittests/contracts/eosio.system/eosio.system.cpp.

Original issue was:

error: case value is not a constant expression because check() is not constexpr.

I tried making check() constexpr in cdt's libraries/eosiolib/core/eosio/check.hpp, but check calls the extern "C" functions eosio_assert which I don't think can be made constexpr.

So I tried updating the EOSIO_DISPATCH to use a series of if () ... else instead of a switch statement. This appears to work, but the EOSIO_DISPATCH still fails on this contract, and it appears that it is because it attempts to dispatch too many actions:

EOSIO_DISPATCH( eosiosystem::system_contract,
// native.hpp (newaccount definition is actually in eosio.system.cpp)
(newaccount)(updateauth)(deleteauth)(linkauth)(unlinkauth)(canceldelay)(onerror)(setabi)
// eosio.system.cpp
      (init)(setram)(setramrate)(setparams)(setpriv)(setalimits)(rmvproducer)(updtrevision)(bidname)(bidrefund)
// rex.cpp
      (deposit)(withdraw)(buyrex)(unstaketorex)(sellrex)(cnclrexorder)(rentcpu)(rentnet)(fundcpuloan)(fundnetloan)
      (defcpuloan)(defnetloan)(updaterex)(consolidate)(rexexec)(closerex)
// delegate_bandwidth.cpp
      (buyrambytes)(buyram)(sellram)(delegatebw)(undelegatebw)(refund)
// voting.cpp
      (regproducer)(unregprod)(voteproducer)(regproxy)
// producer_pay.cpp
      (onblock)(claimrewards)
)

The same macro builds fine if I remove a bunch of the actions. I wonder if we hit a preprocessor recursion limit, but I don't see an option to change it.

[ericpassmore]

Note:start
group: STABILITY
category: TEST
summary: Use explicit type on test contract to work around deduced returned type error.
Note:end