[LLD][ELF] Add test cases for range extension thunks using linker scripts

[peter.smith]

Summary

Test cases for range extension thunks using linker scripts, include:

• OutputSections placed far apart
• OutputSections with location counter expressions
• Multiple large OutputSections
• Orphan sections
• Interaction with the SORT command

[peter.smith]

Updated diff to account for changes in padding between sections and switch to use InputSectionDescriptions rather than OutputSections.

[peter.smith]

This is the final 11/11 patch of the range thunks series.

[ruiu]

You probably want to submit them as part of the patches that implements the actual feature.

[peter.smith]

I've added these tests into D34691 so this revision is no longer needed.