Determine HLoadClass/String load kind early.

This helps save memory by avoiding the allocation of
HEnvironment and related objects for AOT references to
boot image strings and classes (kBootImage* load kinds)
and also for JIT references (kJitTableAddress).

Compiling aosp_taimen-userdebug boot image, the most memory
hungry method BatteryStats.dumpLocked() needs
  - before:
    Used 55105384 bytes of arena memory...
    ...
    UseListNode    10009704
    Environment      423248
    EnvVRegs       20676560
    ...
  - after:
    Used 50559176 bytes of arena memory...
    ...
    UseListNode     8568936
    Environment      365680
    EnvVRegs       17628704
    ...

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing --jit
Bug: 34053922
Change-Id: I68e73a438e6ac8e8908e6fccf53bbeea8a64a077
diff --git a/compiler/driver/compiler_driver.h b/compiler/driver/compiler_driver.h
index d2141e8..ce7ec45 100644
--- a/compiler/driver/compiler_driver.h
+++ b/compiler/driver/compiler_driver.h
@@ -219,12 +219,12 @@
       REQUIRES_SHARED(Locks::mutator_lock_);
 
   // Resolve compiling method's class. Returns null on failure.
-  mirror::Class* ResolveCompilingMethodsClass(
+  ObjPtr<mirror::Class> ResolveCompilingMethodsClass(
       const ScopedObjectAccess& soa, Handle<mirror::DexCache> dex_cache,
       Handle<mirror::ClassLoader> class_loader, const DexCompilationUnit* mUnit)
       REQUIRES_SHARED(Locks::mutator_lock_);
 
-  mirror::Class* ResolveClass(
+  ObjPtr<mirror::Class> ResolveClass(
       const ScopedObjectAccess& soa, Handle<mirror::DexCache> dex_cache,
       Handle<mirror::ClassLoader> class_loader, dex::TypeIndex type_index,
       const DexCompilationUnit* mUnit)
@@ -247,7 +247,8 @@
 
   // Can we fast-path an IGET/IPUT access to an instance field? If yes, compute the field offset.
   std::pair<bool, bool> IsFastInstanceField(
-      mirror::DexCache* dex_cache, mirror::Class* referrer_class,
+      ObjPtr<mirror::DexCache> dex_cache,
+      ObjPtr<mirror::Class> referrer_class,
       ArtField* resolved_field, uint16_t field_idx)
       REQUIRES_SHARED(Locks::mutator_lock_);