Move `VerificationResults` to dex2oat/.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Change-Id: Iff62c9b8c6e553113cbd12765bf0f691bbe24227
diff --git a/dex2oat/common_compiler_driver_test.h b/dex2oat/common_compiler_driver_test.h
index 1ff88e5..b49d18f 100644
--- a/dex2oat/common_compiler_driver_test.h
+++ b/dex2oat/common_compiler_driver_test.h
@@ -31,6 +31,7 @@
 class DexFile;
 class ProfileCompilationInfo;
 class TimingLogger;
+class VerificationResults;
 
 class CommonCompilerDriverTest : public CommonCompilerTest {
  public:
@@ -62,6 +63,7 @@
 
   size_t number_of_threads_ = 2u;
 
+  std::unique_ptr<VerificationResults> verification_results_;
   std::unique_ptr<CompilerDriver> compiler_driver_;
 
  private: