Add EVMC_ALIAS helper to declare symbol alias (e.g. evmc_create) about evmc

[chfast]

What exactly do you mean?

[axic]

EVMC_EXPORT struct evmc_instance* evmc_create_hera(void) EVMC_NOEXCEPT EVMC_ALIAS("evmc_create");

would create two exported functions:

• evmc_create_hera
• evmc_create

[chfast]

But what implementation do you have in mind?

[axic]

I am not fully sure anymore if we need this, perhaps if we suggest that shared libraries are the best way to distribute EVMC VMs and #81 is implemented then it is likely not needed.

[axic]

It seems the closest way doing this on MSVC is with a #pragma linker export statement, which wrapped into a macro is unlikely to work reliably.