This PR adds functionality to the evm t8n to calculate ethash difficulty. If the caller does not provide a currentDifficulty, but instead provides the parentTimestamp (well, semi-optional, will default to 0 if not given), and parentDifficulty, we can calculate it for him.

The caller can also provide a parentUncleHash. In most, but not all cases, the parent uncle hash also affects the formula. If no such hash is provided (or, if the empty all-zero hash is provided), it's assumed that there were no uncles.

The new linter version is built with go 1.17 and thus includes the go vet
check for mismatched +build and go:build lines.

Fortunately, no new warnings are reported with this update.

This reverts commit c368f728.

* core: make txpool reject too sudden changes

* core: add some metrics to txpool

Co-authored-by: Felix Lange <fjl@twurst.com>

Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>

Before:

316M .git/modules/tests/

After:

171M .git/modules/tests/

This fixes a rare crash which could occur when two different errors happened
in the same bloombits.MatcherSession.

In p2p/dial.go, conn.flags was accessed without using sync/atomic.
This race is fixed by removing the access.

In p2p/enode/iter_test.go, a similar race is resolved by writing the field atomically.
Co-authored-by: Felix Lange <fjl@twurst.com>

* core/vm: more detailed benchmark for jumpdest analysis

* core/vm: make jd analysis benchmark alloc free

* core/vm: improve jumpdest analysis

* core/vm: improve worst-case

* core/vm: further improvements in analysis

* core/vm: improve jumpdest analysis >PUSH15

* core/vm: make jd analysis ref by value

* core/vm: fix misspell

* core/vm: improve set8 and set16 a bit

* core/vm: reduce amount of code

* core/vm: optimize byte copying

* eth/gasprice: cache feeHistory results

* eth/gasprice: changed feeHistory block count limitation

* eth/gasprice: do not use embedded struct in blockFees

* eth/gasprice: fee processing logic cleanup

* eth/gasprice: purge feeHistory cache at chain reorgs

Makes the RPC block return the POA sealer for clique blocks on the 'miner' field (was previously zeroes)

Adds --nousb as a deprecated flag when someone runs the geth show-deprecated-flags command.

Removes references to the short-lived Calaveras testnet

cmd, metrics: add support for influxdb-v2 (cherry-picking from italoacasas' changes), leave existing support for v1 to maintain backwards-compatibility. (#23194)

This PR adds flag to enable InfluxDB v2 (--metrics.influxdbv2), flags for v2-specific features (--metrics.influxdb.token, --metrics.influxdb.bucket), also carries over addition of support for specifying organization (--metrics.influxdb.organization), but still retains backwards compatibility with InfluxDB v1.

* tests: update, enable legacy tests, remove vm tests

* tests: minor fixes

* accounts/external: handle 0 chainid as not-set for the Clef API

* accounts/external: document SignTx
Co-authored-by: Felix Lange <fjl@twurst.com>

eth: drop eth/65, the last non-reqid protocol version

* core/rawdb: implement sequential reads in freezer_table

* core/rawdb, ethdb: add sequential reader to db interface

* core/rawdb: lint nitpicks

* core/rawdb: fix some nitpicks

* core/rawdb: fix flaw with deferred reads not being performed

* core/rawdb: better documentation