create transient storage snapshots for process_create_message

[gurukamath]

(closes #917 )

What was wrong?

process_create_message did not create the right snapshots for rollback in case something went wrong.

Related to Issue #917

How was it fixed?

Add transient_storage to Environment and create appropriate snapshots.

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.72%. Comparing base (bf47143) to head (d663e77).
Report is 65 commits behind head on forks/cancun.

Additional details and impacted files

@@               Coverage Diff                @@
##           forks/cancun     #918      +/-   ##
================================================
+ Coverage         69.96%   74.72%   +4.76%     
================================================
  Files               610      611       +1     
  Lines             34295    34897     +602     
================================================
+ Hits              23993    26076    +2083     
+ Misses            10302     8821    -1481     

Flag	Coverage Δ
unittests	74.72% <100.00%> (+4.76%)	⬆️

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[SamWilsn]

Looks good to me, but I'm not super familiar with this part of the code.

[holiman]

@SamWilsn once you rebase the statetest branch to include this, I can fuzz it again and see if it holds up

[petertdavies]

LGTM!

[holiman]

@gurukamath could you explain a bit about the circumstances here? The original testcase was pretty messy, building a very deeply nested calltree.
I'm trying to make a canonical testcase for this (holiman/goevmlab#140) , but would appreciate some guidance.

[gurukamath]

@gurukamath could you explain a bit about the circumstances here? The original testcase was pretty messy, building a very deeply nested calltree.
I'm trying to make a canonical testcase for this (holiman/goevmlab#140) , but would appreciate some guidance.

I believe the case is of the following

1. A does a tstore a value and and tries to create B using CREATE/CREATE2
2. The creation of B fails because len(contract_code) > MAX_CODE_SIZE
3. A then tries to tload the same value as in step 1.
4. sstore then stores this value from tload