fix(debuginfo): Three-way split line records for inlinee-ranges

[calixteman]

When an inline range is strictly included in a parent line record, it must be split into three parts and the end of the original line record must be retained for the last part. This fixes two distinct issues in the previous implementation:

1. The last record was always aligned with the end of the inlinee-range, which either made it too long or left a gap.
2. The third split was also patched with call site information, instead of retaining the original line info.

Before patching:

          +-------------------+
 Parent:  |         P         |
          +---+-----------+---+
Inlinee:      |     I     |
              +-----------+

After patching:

          +---+-----------+---+
 Parent:  | P |     C     | P |
          +-------------------+
Inlinee:      |     I     |
              +-----------+

(P parent line record, C Call site record, I inlinee line record)

Follow-up on #237

[jan-auer]

Thanks, good catch! I checked for this case yesterday, but missed that we create a hole in line records. The bug comes from these lines:

symbolic/debuginfo/src/dwarf.rs

Lines 790 to 793 in ae3aa28

	let size = match lines.get(index) {
	Some(next) => range_end.min(next.address) - range_begin,
	None => range_end - range_begin,
	};

We cap the size of the second half of the line record to the end of the range, but it should use max(size, range_end - start) instead. Do you concur? Changing this one line would probably be a more minimal diff.

[jan-auer]

After discussing this for a while, we figured that your initial patch is indeed the correct solution for this, with one minor change to calculate the length when splitting at the beginning:

let size = record_end.min(range_end) - range_begin;

In the future, a better approach would be to change this even more:

• Operate on ranges with a start and end, rather than start and size. We could use Rust's builtin ranges for this.
• Factor out the range intersection logic into a reusable component that can be unit-tested

In another step, we can consider if we even need to patch the parent line records nowadays.

[jan-auer]

Re-approving after walking through this together with @calixteman