[clang] [llvm] [dyndbg][Clang] Implement nested-ELF dynamic debugging support (PR #194860)

[Stephen Tozer via llvm-commits]

================
@@ -0,0 +1,15 @@
+// By default LLVM gives this section SHF_EXCLUDE, which we don't want. We
+// expect a section named .debug_llvm_dyndbg of type LLVM_DYNDBG_ELF with
+// no flags and alignment of 8 bytes.
+
+// RUN: %clang -cc1 %s -emit-obj -debug-info-kind=limited -fdynamic-debugging -o - -triple x86_64-unknown-unknown | llvm-readelf --section-details - \
+// RUN: | FileCheck %s
+//             [Nr] Name
+// CHECK:      .debug_llvm_dyndbg
+//             Type            Address          Off           Size          ES Lk Inf Al
+// CHECK-NEXT: LLVM_DYNDBG_ELF 0000000000000000 {{[0-9a-z]+}} {{[0-9a-z]+}} 00 0  0   8
----------------
SLTozer wrote:

```suggestion
// CHECK-NEXT: LLVM_DYNDBG_ELF 0000000000000000 {{[0-9a-f]+}} {{[0-9a-f]+}} 00 0  0   8
```

https://github.com/llvm/llvm-project/pull/194860