Pull compact-unwind support into llvm-20.

[lhames]

The following patches are needed to add compact-unwind frame info support to ORC. This enables unwinding and exception handling for JIT'd code on Darwin/arm64:

/cherry-pick 7fb233f a1ff2d1 b46211b c0f7ebe b84ac58 52b5e36 9de581b eae6d6d aefa30e 88f55d1 4a2a8ed 9d88ffe 7a213e7 e00f824

[llvmbot]

@llvm/issue-subscribers-orcjit

Author: Lang Hames (lhames)

The following patches are needed to add compact-unwind frame info support to ORC. This enables unwinding and exception handling for JIT'd code on Darwin/arm64:

/cherry-pick 7fb233f a1ff2d1 b46211b c0f7ebe b84ac58 52b5e36 9de581b eae6d6d aefa30e 88f55d1 4a2a8ed 9d88ffe 7a213e7 e00f824

[llvmbot]

@llvm/issue-subscribers-jitlink

Author: Lang Hames (lhames)

The following patches are needed to add compact-unwind frame info support to ORC. This enables unwinding and exception handling for JIT'd code on Darwin/arm64:

/cherry-pick 7fb233f a1ff2d1 b46211b c0f7ebe b84ac58 52b5e36 9de581b eae6d6d aefa30e 88f55d1 4a2a8ed 9d88ffe 7a213e7 e00f824

[llvmbot]

/pull-request #126015