Revert^6 "Hash-based dex cache type array."

Fixed ImageWriter to write class table also if it contains
only boot class loader classes. Added a regression test and
added extra checks for debug-build to verify that dex cache
types from app image are also in the class table. Removed
some unnecessary debug output.

Test: 158-app-image-class-table
Bug: 34839984
Bug: 30627598
Bug: 34659969

This reverts commit 0b66d6174bf1f6023f9d36dda8538490b79c2e9f.

Change-Id: I6a747904940c6ebc297f4946feef99dc0adf930c
diff --git a/compiler/driver/dex_compilation_unit.h b/compiler/driver/dex_compilation_unit.h
index 854927d..24a9a5b 100644
--- a/compiler/driver/dex_compilation_unit.h
+++ b/compiler/driver/dex_compilation_unit.h
@@ -34,7 +34,7 @@
 
 class DexCompilationUnit : public DeletableArenaObject<kArenaAllocMisc> {
  public:
-  DexCompilationUnit(jobject class_loader,
+  DexCompilationUnit(Handle<mirror::ClassLoader> class_loader,
                      ClassLinker* class_linker,
                      const DexFile& dex_file,
                      const DexFile::CodeItem* code_item,
@@ -44,7 +44,7 @@
                      const VerifiedMethod* verified_method,
                      Handle<mirror::DexCache> dex_cache);
 
-  jobject GetClassLoader() const {
+  Handle<mirror::ClassLoader> GetClassLoader() const {
     return class_loader_;
   }
 
@@ -113,7 +113,7 @@
   }
 
  private:
-  const jobject class_loader_;
+  const Handle<mirror::ClassLoader> class_loader_;
 
   ClassLinker* const class_linker_;
 
@@ -125,7 +125,7 @@
   const uint32_t access_flags_;
   const VerifiedMethod* verified_method_;
 
-  Handle<mirror::DexCache> dex_cache_;
+  const Handle<mirror::DexCache> dex_cache_;
 
   std::string symbol_;
 };