Add allocate_bytes and refactor allocate_str in InterpCx for raw byte…
Fixes https://github.com/rust-lang/miri/issues/4025
This PR introduces a new `allocate_bytes` function in InterpCx and refactors `allocate_str` to use it internally. This change improves memory allocation handling in the interpreter by:
1. Adding `allocate_bytes`:
- Direct byte slice allocation support
- Handles both mutable and immutable allocations
- Maintains proper memory alignment and deduplication
2. Refactoring `allocate_str`:
- Now uses `allocate_bytes` internally
- Adds string-specific metadata handling
- Preserves existing string allocation behavior
This is part 1 of the planned changes to improve timezone string handling in Miri. A follow-up PR will update Miri's timezone logic to use this new allocation mechanism.
Related: https://github.com/rust-lang/miri/pull/4069
0d26662fd3