[CIR][CIRGen] fix calling a function through a function pointer

Author: YazZz1k

clang/lib/CIR/CodeGen/CIRGenExpr.cpp

@@ -1145,10 +1145,6 @@ RValue CIRGenFunction::buildCall(clang::QualType CalleeType,
   if (isa<FunctionNoProtoType>(FnType) || Chain) {
     assert(!UnimplementedFeature::chainCalls());
     assert(!UnimplementedFeature::addressSpace());
-
-    // Set no-proto function as callee.
-    auto Fn = llvm::dyn_cast<mlir::cir::FuncOp>(Callee.getFunctionPointer());
-    Callee.setFunctionPointer(Fn);
   }
 
   assert(!CGM.getLangOpts().HIP && "HIP NYI");

clang/test/CIR/CodeGen/no-proto-fun-ptr.c

@@ -15,3 +15,13 @@ void check_noproto_ptr() {
 
 void empty(void) {}
 
+void buz() {
+  void (*func)();
+  (*func)();
+}
+
+// CHECK:  cir.func no_proto @buz()
+// CHECK:    [[FNPTR_ALLOC:%.*]] = cir.alloca !cir.ptr<!cir.func<!void (...)>>, cir.ptr <!cir.ptr<!cir.func<!void (...)>>>, ["func"] {alignment = 8 : i64}
+// CHECK:    [[FNPTR:%.*]] = cir.load deref [[FNPTR_ALLOC]] : cir.ptr <!cir.ptr<!cir.func<!void (...)>>>, !cir.ptr<!cir.func<!void (...)>>
+// CHECK:    cir.call [[FNPTR]]() : (!cir.ptr<!cir.func<!void (...)>>) -> ()
+// CHECK:    cir.return