[llvm] [AArch64][SME] Implement the SME ABI (ZA state management) in Machine IR (PR #149062)

[Mikael Holmén via llvm-commits]

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@@ -0,0 +1,288 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=aarch64-linux-gnu -mattr=+sme -aarch64-new-sme-abi < %s | FileCheck %s
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mikaelholmen wrote:

This testcase fails if llc is built with EXPENSIVE_CHECKS, or if you justr add "-verify-machineinstrs" to the RUN line:
```
*** Bad machine code: Using an undefined physical register ***
- function:    za_with_raii
- basic block: %bb.1 throw_exception (0x563ee44cad28)
- instruction: %12:gpr64 = COPY $x0
- operand 1:   $x0
LLVM ERROR: Found 1 machine code errors.
```

https://github.com/llvm/llvm-project/pull/149062