* eth: improve shutdown synchronization

Most goroutines started by eth.Ethereum didn't have any shutdown sync at
all, which lead to weird error messages when quitting the client.

This change improves the clean shutdown path by stopping all internal
components in dependency order and waiting for them to actually be
stopped before shutdown is considered done. In particular, we now stop
everything related to peers before stopping 'resident' parts such as
core.BlockChain.

* eth: rewrite sync controller

* eth: remove sync start debug message

* eth: notify chainSyncer about new peers after handshake

* eth: move downloader.Cancel call into chainSyncer

* eth: make post-sync block broadcast synchronous

* eth: add comments

* core: change blockchain stop message

* eth: change closeBloomHandler channel type

Prior to this change, eth_call changed the balance of the sender account in the
EVM environment to 2^256 wei to cover the gas cost of the call execution.
We've had this behavior for a long time even though it's super confusing.

This commit sets the default call gasprice to zero instead of updating the balance,
which is better because it makes eth_call semantics less surprising. Removing
the built-in balance assignment also makes balance overrides work as expected.

This fixes a bunch of cases where a timeout in the test would leak
a goroutine.

* node: expose config in service context

* eth: integrate p2p/dnsdisc

* cmd/geth: add some DNS flags

* eth: remove DNS URLs

* cmd/utils: configure DNS names for testnets

* params: update DNS URLs

* cmd/geth: configure mainnet DNS

* cmd/utils: rename DNS flag and fix flag processing

* cmd/utils: remove debug print

* node: fix test

* add regression tests for #20611

* eth/tracers: fix panics occurring for invalid params in js-tracers

Co-authored-by: Martin Holst Swende <martin@swende.se>

This reverts commit a1bc0e3c.

eth, internal/web3ext: add optional first and last arguments to the  `admin_exportChain` RPC. (#20107)

* consensus/ethash, params: implement eip-2384: bump difficulty bomb

* params: EIP 2384 compat checks

* consensus, params: add Muir Glacier block number (mainnet,ropsten) + official name

* core/forkid: forkid tests for muir glacier

* params/config: address review concerns

* params, core/forkid: review nitpicks

* cmd/geth,eth,les: add override option for muir glacier

* params: nit fix

* travis: Enable ARM support

* Include fixes from 20039

* Add a trace to debug the invalid lookup issue

* Try increasing the timeout to see if the arm test passes

* Investigate the resolver issue

* Increase arm64 timeout for clique test

* increase timeout in tests for arm64

* Only test the failing tests

* Review feedback: don't export epsilon

* Remove investigation tricks+include fjl's feeback

* Revert the retry ahead of using the mock resolver

* Fix rebase errors

* core/evm, contracts: avoid copying memory for input in calls + make ecrecover not modify input buffer

* core/vm: optimize mstore a bit

* core/vm: change Get -> GetCopy in vm memory access

When we flush a batch of trie nodes into database during the state
sync, we should guarantee that all children should be flushed before
parent.

Actually the trie nodes commit order is strict by: children -> parent.
But when we flush all ready nodes into db, we don't need the order
anymore since

    (1) they are all ready nodes (no more dependency)
    (2) underlying database provides write atomicity

This change adds support for EIP-1898. 

The precompile at 0x09 wraps the BLAKE2b F compression function:
https://tools.ietf.org/html/rfc7693#section-3.2

The precompile requires 6 inputs tightly encoded, taking exactly 213
bytes, as explained below.

- `rounds` - the number of rounds - 32-bit unsigned big-endian word
- `h` - the state vector - 8 unsigned 64-bit little-endian words
- `m` - the message block vector - 16 unsigned 64-bit little-endian words
- `t_0, t_1` - offset counters - 2 unsigned 64-bit little-endian words
- `f` - the final block indicator flag - 8-bit word

[4 bytes for rounds][64 bytes for h][128 bytes for m][8 bytes for t_0]
[8 bytes for t_1][1 byte for f]

The boolean `f` parameter is considered as `true` if set to `1`.
The boolean `f` parameter is considered as `false` if set to `0`.
All other values yield an invalid encoding of `f` error.

The precompile should compute the F function as specified in the RFC
(https://tools.ietf.org/html/rfc7693#section-3.2) and return the updated
state vector `h` with unchanged encoding (little-endian).

See EIP-152 for details.

* eth, interal, les: add getHeaderBy* APIs

* internal: address the comment

* eth, internal, les: getHeader nits, missing TD, console callable

Fixed assigning values to variables we don't end up using.