[llvm] [RISCV][MC] Implement ISA mapping symbols (PR #67541)

[Jessica Clarke via llvm-commits]

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@@ -152,6 +156,16 @@ void RISCVELFStreamer::emitMappingSymbol(StringRef Name) {
   Symbol->setBinding(ELF::STB_LOCAL);
 }
 
+void RISCVELFStreamer::changeISAMappingSymbol(unsigned Attribute,
+                                              StringRef arch) {
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jrtc27 wrote:

```suggestion
                                              StringRef Arch) {
```

https://github.com/llvm/llvm-project/pull/67541