[tamnd]

The first census runs with the compare job (7.2.8 and 6.12.111, A64 allmodconfig) showed that the differentials were mostly comparing sanitizer instrumentation. arm64 allmodconfig gives gcc's kernel generic KASAN, UBSAN and the shadow call stack. rucc takes no -fsanitize flag, so its kernel gets KASAN in the hardware tag mode and nothing else. Every unit of the gcc build then has --param asan-*, -fsanitize=* and -ffixed-x18 that the rucc build lacks, mm/kasan builds different files, Module.symvers differs in the __asan_* and kasan_* exports, and most section differences come from the instrumented code.

Plan section 8.10 keeps the sanitizers out of the grade, so the census fragments for E10 and E11 now turn off KASAN, UBSAN, the shadow call stack and KCSAN in both builds. KCSAN is on the list because allmodconfig turns it on as soon as KASAN is off.

config-divergences.toml also gets:

• Two [[flags]] entries for the -isystem $(CC) -print-file-name=include path of the NEON units, which names each compiler's own directory.
• Entries for GCC_ASM_GOTO_OUTPUT_BROKEN, CC_HAS_ASM_GOTO_OUTPUT and CC_HAS_ASM_GOTO_TIED_OUTPUT on 6.12. The runner's gcc-12 is 12.4.0 now and has the fix for bug 113921, while rucc claims 12.2.0 for 6.12, which 6.12 calls broken. The GCC_VERSION and GCC_ASM_GOTO_OUTPUT_WORKAROUND reasons are updated to match.

The "K" constraint and -m64 probe differences are fixed in rucc by tamnd/rucc#3765 and tamnd/rucc#3766.

Part of #7.