Add synthetic source locations

[djolertrk]

This adds sveral features/fixes for improved debugging:

1. Synthetic source locations: Compiler-generated code (like local
   initialization, ABI transforms) now uses SourceSpan::SYNTHETIC instead
   of UNKNOWN. This differentiates compiler-generated code from truly
   unknown locations and renders as #loc(synthetic) in output.

2. -Z print-masm-source-locations: New flag to print source locations
   as #loc("file":line:col) annotations in MASM output.

3. -Z remap-path-prefix=FROM=TO: Remap source path prefixes for resolving
   paths from DWARF when sources are in different locations (e.g., stdlib).

4. Use current_span to have more real source locations attached --
   currently we used Default locations a lot - for example, each
   operator would start with it.

5. Fix wasm component-level DWARF parsing

Requires miden-vm with SourceSpan::SYNTHETIC debug type.

To check locations on masm level, use:

$ ./bin/midenc examples/assert-debug-test/target/wasm32-unknown-unknown/release/assert_debug_test.wasm \
    --entrypoint=assert_debug_test::test_assert \
    -Ztrim-path-prefix=examples/assert-debug-test \
    -Zprint-masm-source-locations \
    --debug full --emit=masm=-

[djolertrk]

cc @greenhat @bitwalker

[djolertrk]

This one depends on 0xMiden/miden-vm#2443 (the miden-vm implementation for the debug type) and goes on top of #810 -- where it improves a lot the situation with source locations because of this https://github.com/walnuthq/compiler/blob/pr/synthetic-source-locations-clean/frontend/wasm/src/module/func_translator.rs#L247, and with that we do have source locations attached to ub.unreachable, but the when an assert is triggered, miden-debug still prints in the stack trace.