[clang] [llvm] [MC,llvm-readobj,yaml2obj] Support CREL relocation format (PR #91280)

[James Henderson via llvm-commits]

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@@ -86,6 +86,8 @@ DYNAMIC_TAG(RELRSZ, 35)  // Size of Relr relocation table.
 DYNAMIC_TAG(RELR, 36)    // Address of relocation table (Relr entries).
 DYNAMIC_TAG(RELRENT, 37) // Size of a Relr relocation entry.
 
+DYNAMIC_TAG(CREL,  38)   // CREL relocation table
+
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jh7370 wrote:

I think we need to avoid generic numbers for dynamic tags/section types etc, except possibly generic numbers that are a long way from the "normal" range. The reason for this is we don't know what values are going to get standardised, assuming this feature even gets accepted into the standard. If, for example, another feature gets accepted into the standard before CREL, it might use up the slot you've "allocated" for the DT_CREL here, which could cause problems with loaders that have supported the experimental CREL implementation. On the other hand, a different special number (whether in a dedicated range or otherwise) that isn't adjacent to the list will not have the issue of a potential clash.

https://github.com/llvm/llvm-project/pull/91280