Fix handling of FCalls in ExternalMethodFixupWorker (#17252)
Fix handling of FCalls in ExternalMethodFixupWorker (#17252)

When running ready to run code on ARM, the ExternalMethodFixupWorker
doesn't handle the entrypoints of FCalls correctly. It tries to handle
them as compact entrypoints, but those use a different machine code
instructions and it results in an assert in debug / checked build.

This change detects the runtime supplied calls before trying to check
for the compact entrypoint.
wtgodbe/coreclr,wtgodbe/coreclr,mmitche/coreclr,cshung/coreclr,mmitche/coreclr,poizan42/coreclr,krk/coreclr,poizan42/coreclr,wtgodbe/coreclr,krk/coreclr,poizan42/coreclr,cshung/coreclr,wtgodbe/coreclr,poizan42/coreclr,cshung/coreclr,wtgodbe/coreclr,krk/coreclr,cshung/coreclr,mmitche/coreclr,krk/coreclr,poizan42/coreclr,wtgodbe/coreclr,mmitche/coreclr,poizan42/coreclr,cshung/coreclr,krk/coreclr,krk/coreclr,mmitche/coreclr,cshung/coreclr,mmitche/coreclr