[llvm] [llvm][ELF] Add ELF section type for embedding ELF binaries (PR #207027)

[Peter Smith via llvm-commits]

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@@ -682,6 +682,12 @@ This indicates that `ball` calls `foo`, `bar` and `baz` directly;
 `ball` indirectly calls functions whose types are `4524972987496481828`,
 `3498816979441845844` and `8646233951371320954`.
 
+#### `SHT_LLVM_ELF` Section (ELF binary embedding)
+
+This section is used to embed an ELF binary. The expectation is that the name of
+the section, the nature of the embedded ELF and how it will be processed, will
+be determined by the use case, e.g. ELF dynamic debugging.
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smithp35 wrote:

No objections. FWIW I agree with @jh7370 that ELF conventions are for the type to encode the action a linker should take, and name is used for collating similarly named sections. It is rare for the section name to be significant.

`SHD_LLVM_DYN_DBG_ELF` sounds OK to me, especially if there are other option names with dyn-dbg in it. If the options use dyndbg without the separator, would be good to use that.

https://github.com/llvm/llvm-project/pull/207027