* introduce wasm_runtime_instantiate_ex2
at this point, just a slightly inefficiant functionality
equivalent of wasm_runtime_instantiate_ex.
however, unlike wasm_runtime_instantiate_ex, this one is designed
to be extendable without breaking the user-visible ABI.
because the definition of InstantiationArgs2 is not exposed to
users, we can safely add new members to it.
this commit also makes wasm_runtime_instantiate_ex a wrapper
of wasm_runtime_instantiate_ex2.
if this goes well, maybe it's a good idea to apply a similar
pattern to RuntimeInitArgs, LoadArgs, SharedHeapInitArgs, etc.
i started with InstantiationArgs just because i happen to have
a need to extend it for wasi-nn.
cf.
https://github.com/bytecodealliance/wasm-micro-runtime/issues/4364https://github.com/bytecodealliance/wasm-micro-runtime/issues/4331
* product-mini/platforms/posix: use wasm_runtime_instantiate_ex2
5d48cfdbc0