This has the drawback of traversing expression each time the argument is
used. However this is not the case in our syscall/native wrappers.
The old behaviour can be restored by explicit local assignment.
Consider function call `f(1, g(2, 3))` when
both `f` and `g` are inlined. If `f` contains some locals,
inlining `g` will replace them with it's another locals map,
because slices in Go reuse storage on `append`.
Thus scope needs to be copied.
Some control-flow statements drop stack items, for example
`return` when it is used inside of `range` loop.
For inlined calls this `return` should drop only portion of stack
which belongs to inlined call.
When function call-site parameter is an identifier,
we may load it directly. Currently it can be also modified,
this will be fixed in a separate commit.
