[wasm] Provide backoff implementations for the Fxx rounding instructions

test/cctest/compiler/codegen-tester.h

Index: test/cctest/compiler/codegen-tester.h
diff --git a/test/cctest/compiler/codegen-tester.h b/test/cctest/compiler/codegen-tester.h
index 442845426279a96afd2925232f68845bd3e194c4..b440c6b4b6428fd1317c8bf9a579dae450cfcd19 100644
--- a/test/cctest/compiler/codegen-tester.h
+++ b/test/cctest/compiler/codegen-tester.h
@@ -40,6 +40,8 @@ class RawMachineAssemblerTester : public HandleAndZoneScope,
             MachineType::PointerRepresentation(),
             InstructionSelector::SupportedMachineOperatorFlags()) {}
 
+  virtual ~RawMachineAssemblerTester() {}
+
   void CheckNumber(double expected, Object* number) {
     CHECK(this->isolate()->factory()->NewNumber(expected)->SameValue(number));
   }
@@ -86,6 +88,7 @@ class BufferedRawMachineAssemblerTester
       : BufferedRawMachineAssemblerTester(ComputeParameterCount(p0, p1, p2, p3),
                                           p0, p1, p2, p3) {}
 
+  virtual byte* Generate() { return RawMachineAssemblerTester::Generate(); }
 
   // The BufferedRawMachineAssemblerTester does not pass parameters directly
   // to the constructed IR graph. Instead it passes a pointer to the parameter
@@ -245,6 +248,8 @@ class BufferedRawMachineAssemblerTester<void>
                               : Load(p3, RawMachineAssembler::Parameter(3));
   }
 
+  virtual byte* Generate() { return RawMachineAssemblerTester::Generate(); }
+
   // The BufferedRawMachineAssemblerTester does not pass parameters directly
   // to the constructed IR graph. Instead it passes a pointer to the parameter
   // to the IR graph, and adds Load nodes to the IR graph to load the
@@ -523,7 +528,8 @@ class BinopGen {
 // and run the generated code to ensure it produces the correct results.
 class Int32BinopInputShapeTester {
  public:
-  explicit Int32BinopInputShapeTester(BinopGen<int32_t>* g) : gen(g) {}
+  explicit Int32BinopInputShapeTester(BinopGen<int32_t>* g)
+      : gen(g), input_a(0), input_b(0) {}
 
   void TestAllInputShapes();