Fix memory leaks in MLIR unit-tests (NFC)

Author: joker-eph

mlir/test/CAPI/pass.c

@@ -189,6 +189,8 @@ void testParsePassPipeline() {
   mlirPrintPassPipeline(mlirPassManagerGetAsOpPassManager(pm), printToStderr,
                         NULL);
   fprintf(stderr, "\n");
+  mlirPassManagerDestroy(pm);
+  mlirContextDestroy(ctx);
 }
 
 int main() {

mlir/unittests/Rewrite/PatternBenefit.cpp

@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "mlir/IR/OwningOpRef.h"
 #include "mlir/IR/PatternMatch.h"
 #include "mlir/Rewrite/PatternApplicator.h"
 #include "gtest/gtest.h"
@@ -20,7 +21,7 @@ TEST(PatternBenefitTest, BenefitOrder) {
   MLIRContext context;
 
   OpBuilder builder(&context);
-  auto module = ModuleOp::create(builder.getUnknownLoc());
+  OwningOpRef<ModuleOp> module = ModuleOp::create(builder.getUnknownLoc());
 
   struct Pattern1 : public OpRewritePattern<ModuleOp> {
     Pattern1(mlir::MLIRContext *context, bool *called)
@@ -71,7 +72,7 @@ TEST(PatternBenefitTest, BenefitOrder) {
   };
 
   MyPatternRewriter rewriter(&context);
-  (void)pa.matchAndRewrite(module, rewriter);
+  (void)pa.matchAndRewrite(*module, rewriter);
 
   EXPECT_TRUE(called1);
   EXPECT_TRUE(called2);