fix heap cost calculation rounding error

[tao-stones]

Problem

Should round up heap size to next 32k block before div

Summary of Changes

• refactor the heap cost into a function
• add test with refraction heap size (the 3rd case would fail before fix)
• fix size truncation by round up to next 32K block first
• add feature gate
• check result of consume_checked if feature is activated

OPTIONAL: Feature Gate Issue: #30679

[tao-stones]

@Lichtso if this is a valid change, it probably needs a feature gate, or perhaps can be rolled into other feature gates if possible?

[Lichtso]

Yes, it needs a feature gate, and I can't think of any other related one to merge this change into.

[tao-stones]

Yes, it needs a feature gate, and I can't think of any other related one to merge this change into.

Thanks for quick response. Feature gate added.

[codecov]

Codecov Report

Merging #30673 (cd245fd) into master (04e52f5) will decrease coverage by 0.1%.
The diff coverage is 97.0%.

@@            Coverage Diff            @@
##           master   #30673     +/-   ##
=========================================
- Coverage    81.6%    81.6%   -0.1%     
=========================================
  Files         723      723             
  Lines      201672   201646     -26     
=========================================
- Hits       164766   164744     -22     
+ Misses      36906    36902      -4