Nightly build 2024.12.13

What's Changed

Toolchain and implementation changes 🛠️

• Add Dump functions to Check, Parse, and Lex by @jonmeow in #4669
• Allow defining .h files in tests without trying to compile them as Carbon files by @bricknerb in #4667
• Lower global variables as global definitions, not global declarations. by @zygoloid in #4674
• Import support for array types. by @zygoloid in #4675
• Support stringifying tuple values. by @zygoloid in #4664
• Use a filename without a line number as a cue for autoupdate. by @jonmeow in #4677
• Clean up missing library in test by @jonmeow in #4678

Full Changelog: v0.0.0-0.nightly.2024.12.12...v0.0.0-0.nightly.2024.12.13