[clang] [RISCV] Allow YAML file to control multilib selection (PR #98856)

[Sam Elliott via cfe-commits]

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@@ -258,6 +259,13 @@ static void getARMMultilibFlags(const Driver &D,
   }
 }
 
+static void getRISCVMultilibFlags(const Driver &D, const llvm::Triple &Triple,
+                                  const llvm::opt::ArgList &Args,
+                                  Multilib::flags_list &Result) {
+  Result.push_back("-march=" + riscv::getRISCVArch(Args, Triple));
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lenary wrote:

I think that the arch string used here should be normalised using RISCVISAInfo - so that matching is much easier. I think this might throw up some issues when clang changes the version of an extension it implements, but likely you have to check your library build/configuration when that happens anyway, i think.

https://github.com/llvm/llvm-project/pull/98856