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

[Fangrui Song via cfe-commits]

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@@ -61,6 +61,9 @@ class MCTargetOptions {
 
   bool Dwarf64 : 1;
 
+  // Use CREL relocation format for ELF.
+  bool Crel = false;
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MaskRay wrote:

If LLVM adopts https://llvm.org/docs/Proposals/VariableNames.html , I'd like to use `crel` instead of `cRel`. But with the capitalized naming, I'd prefer `Crel`. This makes many functions' names `xxxCrels` align better with `xxxRels`.

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