Revert "Revert "Add basic image writer support for app images""

No changes, bug fixed in:
https://android-review.googlesource.com/#/c/180886/

Bug: 22858531

This reverts commit 4b018565e57c3349a3c1b5ec8ac9dae261c5e00b.

Change-Id: I86d9c2b55d535d803c6e1b3b8b4836bf6ff077e5
diff --git a/compiler/driver/compiler_driver.h b/compiler/driver/compiler_driver.h
index 07cd077..5683b03 100644
--- a/compiler/driver/compiler_driver.h
+++ b/compiler/driver/compiler_driver.h
@@ -92,7 +92,7 @@
                  Compiler::Kind compiler_kind,
                  InstructionSet instruction_set,
                  const InstructionSetFeatures* instruction_set_features,
-                 bool image, std::unordered_set<std::string>* image_classes,
+                 bool boot_image, std::unordered_set<std::string>* image_classes,
                  std::unordered_set<std::string>* compiled_classes,
                  std::unordered_set<std::string>* compiled_methods,
                  size_t thread_count, bool dump_stats, bool dump_passes,
@@ -153,8 +153,8 @@
   }
 
   // Are we compiling and creating an image file?
-  bool IsImage() const {
-    return image_;
+  bool IsBootImage() const {
+    return boot_image_;
   }
 
   const std::unordered_set<std::string>* GetImageClasses() const {
@@ -634,7 +634,7 @@
   // in the .oat_patches ELF section if requested in the compiler options.
   size_t non_relative_linker_patch_count_ GUARDED_BY(compiled_methods_lock_);
 
-  const bool image_;
+  const bool boot_image_;
 
   // If image_ is true, specifies the classes that will be included in
   // the image. Note if image_classes_ is null, all classes are