[clang] [CIR] Generalize the special member attribute into func_info and add a callee resolver (PR #207261)

[Rithik Sharma via cfe-commits]

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@@ -1051,6 +1051,27 @@ unsigned cir::CallOp::getNumArgOperands() {
   return this->getOperation()->getNumOperands();
 }
 
+static cir::FuncOp resolveCalleeImpl(mlir::Operation *op,
+                                     mlir::SymbolTableCollection *symbolTable) {
+  auto callee = op->getAttrOfType<mlir::FlatSymbolRefAttr>(
+      CIRDialect::getCalleeAttrName());
+  if (!callee)
+    return {};
+
+  if (symbolTable)
+    return symbolTable->lookupNearestSymbolFrom<cir::FuncOp>(op, callee);
+  return mlir::SymbolTable::lookupNearestSymbolFrom<cir::FuncOp>(op, callee);
----------------
SharmaRithik wrote:

It works. `lookupNearestSymbolFrom` takes any op and walks up to the nearest symbol table by itself, so the call op is enough. `verifyCallCommInSymbolUses` in this file does the same thing, and the unit test covers it.

https://github.com/llvm/llvm-project/pull/207261