Upgrade tests to the latest debug info format.

Mostly this is just changing the named metadata (llvm.dbg.sp, llvm.dbg.gv,
llvm.dbg.<func>.lv, etc -> llvm.dbg.cu), adding a few fields to older records
(DIVariable: flags/inlined-at, DICompileUnit: sp/gv/types,
DISubprogram: local variables list)

The tests to update were discovered by a change I'm working on to remove debug
info version support - so any tests using old debug info versions I haven't
updated probably are bad tests or just not actually designed to test debug
info.