dat: fix symbol ordering, format generated source in-place

[ribbanya]

• No header code in base objects: jobj.h redeclared the static inline HSD_JObjRefThis without inline, which made clang emit it (and iref_INC, with its assert's file name) wherever the header is included. samples report lists anything a base object has outside .data.
• The base object's .data is laid out in the target's order, so objdiff's section match agrees with the per-symbol one. clang lays variables out where an initializer first points to them, not where they are defined, so each unit is compiled with -fdata-sections and linked (ld.lld -r) with target/.ld, which samples slice writes. Every unit's .data bytes now equal the target's.
• Formatting in place: codegen writes src/ and the format step formats it there, with a stamp in stamp/, so there is one set of generated sources.

Also:

• The build runs without the dev shell's environment, as objdiff runs it: NEWLIB_INCLUDE and AURORA_SRC are cached (from the environment when set; configuring without them fails), and the LLVM tools and cargo are found by absolute path. Configuring through a symlinked path fails: the build then names files by two paths, and ninja reran CMake and rebuilt everything on every build.
• User-side switches in the build's cache: MELEE_DAT_SAMPLES_ALL (archive globs) samples every typed object of those archives, and MELEE_DAT_SAMPLES_EXCLUDE (type globs) keeps types out of the samples.
• objdiff is pinned to v3.8.2, which no longer needs the Cargo.lock patch.

11237 of 11239 samples match, as before; the DOL still matches.