Add heuristic to skip jumpdest analysis

[chfast]

We can guess that the jumpdest analysis is not needed by inspecting the first opcode. This heuristic has some false negatives but is very cheap and covers EOF. The proof it is correct is done at compile-time.

Bigger idea behind this is to only use the heuristic not to waste time on jumpdest analysis and delay EOF header parsing until execution. This makes the code analysis EVM revision agnostic. Maybe someone can push this idea further.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.30%. Comparing base (080a341) to head (aee1c86). Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #990   +/-   ##
=======================================
  Coverage   94.29%   94.30%           
=======================================
  Files         144      144           
  Lines       16155    16159    +4     
=======================================
+ Hits        15234    15238    +4     
  Misses        921      921           

Flag	Coverage Δ
eof_execution_spec_tests	16.72% <100.00%> (+0.02%)	:arrow_up:
ethereum_tests	26.63% <100.00%> (+0.01%)	:arrow_up:
ethereum_tests_silkpre	18.69% <100.00%> (+0.01%)	:arrow_up:
execution_spec_tests	17.78% <100.00%> (+0.02%)	:arrow_up:
unittests	89.74% <100.00%> (+<0.01%)	:arrow_up:

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Files with missing lines	Coverage Δ
lib/evmone/baseline_analysis.cpp	100.00% <100.00%> (ø)
lib/evmone/baseline_instruction_table.cpp	100.00% <100.00%> (ø)
test/unittests/instructions_test.cpp	88.88% <ø> (ø)