This commit is a preparation for the upcoming metropolis hardfork. It
prepares the state, core and vm packages such that integration with
metropolis becomes less of a hassle.
* Difficulty calculation requires header instead of individual
parameters
* statedb.StartRecord renamed to statedb.Prepare and added Finalise
method required by metropolis, which removes unwanted accounts from
the state (i.e. selfdestruct)
* State keeps record of destructed objects (in addition to dirty
objects)
* core/vm pre-compiles may now return errors
* core/vm pre-compiles gas check now take the full byte slice as argument
instead of just the size
* core/vm now keeps several hard-fork instruction tables instead of a
single instruction table and removes the need for hard-fork checks in
the instructions
* core/vm contains a empty restruction function which is added in
preparation of metropolis write-only mode operations
* Adds the bn256 curve
* Adds and sets the metropolis chain config block parameters (2^64-1)
Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.
In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.
* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test
Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.
In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.
* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test
