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

[Fangrui Song via cfe-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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MaskRay wrote:

> it might use up the slot you've "allocated"

I understand the concern but this is just impossible given the essential state of the generic ABI...

(I have some notes at https://maskray.me/blog/2024-05-26-evolution-of-elf-object-file-format#a-future-in-flux)

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