[compiler-rt] [compiler-rt][ARM] Make ARMv4T assembly builtins interwork (PR #221725)

[Ties Stuij via llvm-commits]

stuij wrote:

v4t thumb support is currently a bit academic. I'm not aware of anyone actually building or trying to build the builtins for v4t thumb. arm-toolchain doesn't have a target for it out of the box, GCC doesn't build for it. And currently some builtins are broken for v4t thumb, although I'm planning to fix those in the future. I did test the v4t thumb builtins locally.

https://github.com/llvm/llvm-project/pull/221725