amd64: fixes huge memory offset consts handling (#733)

Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>

internal/integration_test/fuzzcases/fuzzcases_test.go

@@ -298,3 +298,35 @@ func Test730(t *testing.T) {
 		}
 	})
 }
+
+func Test733(t *testing.T) {
+	run(t, func(t *testing.T, r wazero.Runtime) {
+		mod, err := r.InstantiateModuleFromBinary(ctx, getWasmBinary(t, 733))
+		require.NoError(t, err)
+
+		name := "out of bounds"
+		t.Run(name, func(t *testing.T) {
+			f := mod.ExportedFunction(name)
+			require.NotNil(t, f)
+			_, err = f.Call(ctx)
+			require.Error(t, err)
+			require.Contains(t, err.Error(), "out of bounds memory")
+		})
+
+		// Note: this case uses large memory space, so can be slow like 1 to 2 seconds.
+		name = "store higher offset"
+		t.Run(name, func(t *testing.T) {
+			f := mod.ExportedFunction(name)
+			require.NotNil(t, f)
+			_, err = f.Call(ctx)
+			require.NoError(t, err)
+
+			mem := mod.Memory()
+			require.NotNil(t, mem)
+
+			v, ok := mem.ReadUint64Le(ctx, 0x80000100)
+			require.True(t, ok)
+			require.Equal(t, uint64(0xffffffffffffffff), v)
+		})
+	})
+}