arm64 unimplemented instructions

[Talos878]

There appears to be a couple unimplemented arm64 instructions between ida and capstone. These are from ida

21 7d a8 c8 CAS X8, X1, [X9]
08 81 3f b8 SWP WZR, W8, [X8]
08 31 29 f8 LDSET X9, X8, [X8]
08 01 29 b8 LDADD W9, W8, [X8]
20 7d 22 48 CASP X2, X3, X0, X1, [X9]
08 11 29 f8 LDCLR X9, X8, [X8]
08 01 69 b8 LDADDL W9, W8, [X8]
20 81 68 f8 SWPL X8, X0, [X9]
61 7e e9 88 CASA W9, W1, [X19]
08 01 a9 f8 LDADDA X9, X8, [X8]
21 fd aa c8 CASL X10, X1, [X9]

[Rot127]

Those will be added in v6 with #2026
If everything runs smoothly #2026 should be merged into next in during August.

Please note, that this will come with a big refactor of the AArch64 module itself. See https://github.com/Rot127/capstone/blob/v6-release-guide/docs/cs_v6_release_guide.md