Fix MLIR Toy tutorial JIT example and add a test to cover it

Author: joker-eph

mlir/examples/toy/Ch6/toyc.cpp

@@ -240,7 +240,7 @@ int runJit(mlir::ModuleOp module) {
   auto &engine = maybeEngine.get();
 
   // Invoke the JIT-compiled function.
-  auto invocationResult = engine->invoke("main");
+  auto invocationResult = engine->invokePacked("main");
   if (invocationResult) {
     llvm::errs() << "JIT invocation failed\n";
     return -1;

mlir/examples/toy/Ch7/toyc.cpp

@@ -241,7 +241,7 @@ int runJit(mlir::ModuleOp module) {
   auto &engine = maybeEngine.get();
 
   // Invoke the JIT-compiled function.
-  auto invocationResult = engine->invoke("main");
+  auto invocationResult = engine->invokePacked("main");
   if (invocationResult) {
     llvm::errs() << "JIT invocation failed\n";
     return -1;

mlir/test/Examples/Toy/Ch6/jit.toy

@@ -0,0 +1,5 @@
+# RUN: toyc-ch6 -emit=jit %s
+
+def main() {
+ print([[1, 2], [3, 4]]);
+}

mlir/test/Examples/Toy/Ch7/jit.toy

@@ -0,0 +1,5 @@
+# RUN: toyc-ch7 -emit=jit %s
+
+def main() {
+ print([[1, 2], [3, 4]]);
+}