Add per array size allocation entrypoints.

- Update architectures that have fast paths for
  array allocation to use it.
- Will add more fast paths in follow-up CLs.

Test: test-art-target test-art-host.
Change-Id: I138cccd16464a85de22a8ed31c915f876e78fb04
diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index 2d129af..b912672 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -573,6 +573,8 @@
   uint32_t GetReferenceSlowFlagOffset() const;
   uint32_t GetReferenceDisableFlagOffset() const;
 
+  static QuickEntrypointEnum GetArrayAllocationEntrypoint(Handle<mirror::Class> array_klass);
+
  protected:
   // Patch info used for recording locations of required linker patches and their targets,
   // i.e. target method, string, type or code identified by their dex file and index.