CREATE gas cost fix

[OlivierBBB]

CREATE-instructions that raise the failure condition F, in particular at the onset of the CREATE-type instruction, i.e. whenever

$$\sigma[a] \neq \varnothing \wedge \Big[ \sigma[a] _ {\text{n}} \neq 0 \vee \sigma[a] _ {\text{c}} \neq \texttt{KECCAK}(()) \Big]$$

• spec update: Bugfix for GAS_NEXT of CREATE's #15
• constraints update: CREATE gas cost fix linea-constraints#519