[lld] [llvm] [lld][AArch64][Build Attributes] Add support for AArch64 Build Attributes (PR #144082)

[Peter Smith via llvm-commits]

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@@ -0,0 +1,62 @@
+// RUN: rm -rf %t && split-file %s %t && cd %t
+
+// RUN: llvm-mc -triple=aarch64 -filetype=obj %s -o %t11.o
+// RUN: llvm-mc -triple=aarch64 -filetype=obj merged-mixed-2.s -o %t12.o
+// RUN: llvm-mc -triple=aarch64 -filetype=obj merged-mixed-3.s -o %t13.o
+// RUN: ld.lld -r %t11.o %t12.o %t13.o -o %t.merged1.o
+// RUN: llvm-readelf -n %t.merged1.o | FileCheck %s --check-prefix=NOTE-MIXED
+
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smithp35 wrote:

Will be worth a short comment explaining the purpose of the test.
```
Combine a file with build attributes with two files containing (different) GNU properties. All three files describe the same set of AND features so we expect these to propagate to the output. Only
one file has PAuth, so we expect that to be propagated as absence of PAuth information is by default ignored. 
```

https://github.com/llvm/llvm-project/pull/144082