Staging big changes for 2.2.0

[wtdcode]

A playground to make the huge changes together.

TODO:

• [ ]: Bump TCI to 5.1.0 #2050

[wtdcode]

#2021 is having conflicts.

[wtdcode]

#1918 conflicts too but seems easy to merge.

[wtdcode]

#1903 is not resolved yet and there is no CI for loongarch.

I have a side project for local testing: https://github.com/wtdcode/DebianOnQEMU?tab=readme-ov-file#loongarch64

[amaanq]

To fix the conflicts for #2021, on line 728 in qemu/tcg/tcg.h, it should be

    TCGv cpu_gpr[32], cpu_pc, cpu_vl; // also target/mips/translate.c, target/avr/translate.c

I had added cpu_vl for RISC-V (from 5.1.0), so that should stay

[wtdcode]

TODO: Move all

DEF_HELPER_4(uc_tracecode, void, i32, i32, ptr, i64)
DEF_HELPER_6(uc_traceopcode, void, ptr, i64, i64, i32, ptr, i64)

to tcg-runtime.h.

[wtdcode]

TODO: We should have 2.2.0rc1

[wtdcode]

TODO: Format code when we are ready.