## Why this should be merged
Simplifies the creation and application of variadic options; this is
also applicable to many of my other WIP branches (e.g. `snapshot`).
## How this works
See `libevm/options/options.go`, which is very simple.
## How this was tested
Existing tests of `vm.PrecompileEnvironment.Call()`, which itself uses
refactored options.
## Why this should be merged
Fixes tracing when a stateful precompile calls another contract that
itself accesses storage.
## How this works
The pre-state tracer from `eth/tracers/native` doesn't implement
`CaptureEnter()` (entry of a new context), instead relying on
`CaptureState()` (per-opcode tracing) to detect that a new contract has
been entered. In doing so, it [maintains an
invariant](cb7eb89341/eth/tracers/native/prestate.go (L160))
that is expected when `CaptureState(vm.SLOAD, ...)` is called—breaking
the invariant results in a panic due to a nil map.
The fix involves (a) maintaining the invariant as part of
`CaptureEnter()` (previously a no-op); and (b) calling said method
inside `vm.PrecompileEnvironment.Call()`. The latter has the added
benefit of properly handling all tracing involving an outbound call from
precompiles.
## How this was tested
New integration test demonstrates that the tracer can log the retrieved
storage value.
---------
Co-authored-by: Darioush Jalali <darioush.jalali@avalabs.org>
* fix: `vm.WithUNSAFECallerAddressProxying` under `DELEGATECALL`
* test: `vm.WithUNSAFECallerAddressProxying()` effect on outgoing caller addr
* chore: mark `eth/tracers/js` test flaky
* feat: `vm.PrecompileEnvironment.IncomingCallType()`
* chore: minor documentation edit
* doc: `PrecompileEnvironment` example for determining actual caller
* chore: placate the linter
