Missing test cases

@0xTylerHolmes ran the EEST tests with code coverage on geth and there are a bunch of things that are not yet covered by the tests.

# EVM opcodes
- push* opcodes at the end of the bytecode
- codeOffset overflows uint64 in codecopy, extcodecopy and returndatacopy
- offset overflows uint64 in calldataload
- opSAR shift greater than 256, with value 0, positive, all bits set
- opSHR, opSHL with shift > 256
- opSLT with x > y opSGT with x < y
# Memory
- memoryGas overflow is not covered at all (so all opcodes that expand memory)
- memSize over 0x1FFFFFFFE0
# Precompiles
- ecrecover with a correct signature
- modexp with max(modulus, base) > 64 bit and < 1024 bit
- modexp with exponent > 32 bit and len(input) > baselength
- modexp with exponent > 32 bit
- modexp with modulo length < base length
- bn256Pairing with multiple pairings
# outer EVM
- hit call create depth in CALLCODE, DELEGATECALL, STATICCALL, CREATE
- out of balance in CALLCODE, CREATE,
- nonce overflow in CREATE
- mox code size exceeded in CREATE, CREATE2