Add cases where same-named local aliases instantiate generic functions,
local types, and methods with float32 and float64. Record the current
collisions and incorrect results.
For some reason, these aren't lowered when a generic function is
instantiated by the SSA package.
I've left unsafe.Offsetof to be implemented later, it's a bit difficult
to do correctly the way the code is currently structured.
Without this change, the compiler would probably have worked just fine
but the generated types would look odd.
You can see in the test case that it now doesn't use `main.Point` but
rather the correct `main.Poin[float32]` etc.