fix(gnovm): forbid star expression when value is nil

[omarsy]

close: #3052

Contributors' checklist...

• Added new tests, or not needed, or not feasible
• Provided an example (e.g. screenshot) to aid review or the PR is self-explanatory
• Updated the official documentation or not needed
• No breaking changes were made, or a BREAKING CHANGE: xxx message was included in the description
• Added references to related issues and PRs
• Provided any useful hints for running manual tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 63.30%. Comparing base (e9640ef) to head (421a4ac).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3053      +/-   ##
==========================================
- Coverage   63.31%   63.30%   -0.01%     
==========================================
  Files         548      548              
  Lines       78509    78511       +2     
==========================================
- Hits        49705    49700       -5     
- Misses      25450    25455       +5     
- Partials     3354     3356       +2     

Flag	Coverage Δ
contribs/gnodev	59.94% <ø> (-0.63%)	⬇️
contribs/gnofaucet	14.82% <ø> (-0.95%)	⬇️
gno.land	67.18% <ø> (ø)
gnovm	67.88% <100.00%> (+<0.01%)	⬆️
misc/genstd	79.72% <ø> (ø)
tm2	62.40% <ø> (+0.08%)	⬆️

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