arm/arm64: Clean up intrinsic slow paths.

Generalize and use the slow path template IntrinsicSlowPath
from intrinsics_utils.h.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: aosp_taimen-userdebug boot image is unchanged.
Change-Id: Ia8fa4e1b31c1f190fc5f02671336caec15e4cf4d
diff --git a/compiler/optimizing/code_generator_arm64.h b/compiler/optimizing/code_generator_arm64.h
index 8349732..487d091 100644
--- a/compiler/optimizing/code_generator_arm64.h
+++ b/compiler/optimizing/code_generator_arm64.h
@@ -668,10 +668,7 @@
   void GenerateVirtualCall(
       HInvokeVirtual* invoke, Location temp, SlowPathCode* slow_path = nullptr) override;
 
-  void MoveFromReturnRegister(Location trg ATTRIBUTE_UNUSED,
-                              DataType::Type type ATTRIBUTE_UNUSED) override {
-    UNIMPLEMENTED(FATAL);
-  }
+  void MoveFromReturnRegister(Location trg, DataType::Type type) override;
 
   // Add a new boot image intrinsic patch for an instruction and return the label
   // to be bound before the instruction. The instruction will be either the