[mlir][MLProgram][NFC] Migrate to OpAsmAttrInterface for ASM alias generation

Author: ZenithalHourlyRate

mlir/include/mlir/Dialect/MLProgram/IR/MLProgramAttributes.td

@@ -40,6 +40,9 @@ def MLProgram_ExternAttr : MLProgram_Attr<"Extern", [TypedAttrInterface]> {
   let parameters = (ins AttributeSelfTypeParameter<"">:$type);
   let mnemonic = "extern";
   let assemblyFormat = "";
+
+  // Generate mnemonic alias for the attribute.
+  let genMnemonicAlias = 1;
 }
 
 #endif // MLPROGRAM_ATTRIBUTES

mlir/lib/Dialect/MLProgram/IR/MLProgramDialect.cpp

@@ -39,14 +39,6 @@ struct MLProgramInlinerInterface : public DialectInlinerInterface {
 
 struct MLProgramOpAsmDialectInterface : public OpAsmDialectInterface {
   using OpAsmDialectInterface::OpAsmDialectInterface;
-
-  AliasResult getAlias(Attribute attr, raw_ostream &os) const override {
-    if (llvm::isa<ExternAttr>(attr)) {
-      os << "extern";
-      return AliasResult::OverridableAlias;
-    }
-    return AliasResult::NoAlias;
-  }
 };
 } // namespace