Seemingly contradictory code in sharedRuntime.cpp

[Julian Waters]

Hi David,

Thanks for pointing that out. This means that something interesting is
happening, as the code that is protected by the ifdef block has a
comment suggesting that it is solely meant for Windows x64, and not
any 64 bit Windows platform that could include ARM64. This possibly
means that the ARM64 implementation is using the x64 implementation,
with unknown consequences

best regards,
Julian