Add support for `from_utf8` and string handling

[Stevengre]

The from_utf8 function from Rust's stdlib is currently not included in our SMIR JSON because it is not polymorphic. This function is essential for UTF-8 string conversion and will be needed for proper string support in the system.

Current Situation

• from_utf8 is a non-polymorphic stdlib function (source)
• The function internally uses transmute (visible in the _unchecked version)
• String support is currently not implemented in the system
• Functions like amount_to_ui_amount and ui_amount_to_amount will require string support

Technical Details

The from_utf8 function performs UTF-8 validation and conversion from byte arrays to strings. Since it ultimately calls transmute for the unsafe conversion, special handling may be required when implementing this in SMIR.

Tasks

• Analyze the special handling needed for transmute operations in from_utf8
• Implement string type support in SMIR
• Add from_utf8 function support
• Update amount_to_ui_amount and ui_amount_to_amount to handle strings
• Add appropriate test cases for string conversions

Priority

Low/Medium - Marked as non-urgent task, but will be required for full functionality

Related Components

• SMIR JSON serialization
• Standard library function support
• String type handling
• Functions: amount_to_ui_amount, ui_amount_to_amount

References

• Rust stdlib from_utf8 source: https://doc.rust-lang.org/src/core/str/converts.rs.html#89

Labels

enhancement, stdlib-support, type-system, non-urgent