Revert "Make dex2dex return a CompiledMethod after quickening."

Build failures on arm/arm64.

This reverts commit 6920703c8eae0d90528ea09945e742582b6f8198.

Change-Id: I0dd5426610150937dac6e4d9dd9aa759bdf7fca4
diff --git a/compiler/compiled_method.cc b/compiler/compiled_method.cc
index f33db09..d1acada 100644
--- a/compiler/compiled_method.cc
+++ b/compiler/compiled_method.cc
@@ -27,7 +27,8 @@
 }
 
 void CompiledCode::SetCode(const ArrayRef<const uint8_t>* quick_code) {
-  if (quick_code != nullptr && !quick_code->empty()) {
+  if (quick_code != nullptr) {
+    CHECK(!quick_code->empty());
     if (owns_code_array_) {
       // If we are supposed to own the code, don't deduplicate it.
       CHECK(quick_code_ == nullptr);