Otherwise, it's complicated to work with nested lambdas:
outer/inner ones may be replaced independently and still refer
to the old one instances.
So in the changed test, if we don't apply the commit, will remain
implicit return and receiver types for the nested lambda
Anyway, once we decided to leave immutable semantics,
replacements are not necessary anymore
With the mangling added in 488418d960, there's no longer any risk in
writing "special" function name ("<anonymous>" in this case) to the
local variable table.
#KT-34356 Fixed