Implement Reference.getReferent() intrinsic.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing --jit
Test: aosp_blueline-userdebug boots.
Test: run-gtests.sh
Test: testrunner.py --target --optimizing --jit
Bug: 170286013
Change-Id: I4762f7c1cf3d61de2215ec8f1d14be80289c2372
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index 00b2586..1dedfc5 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -8893,12 +8893,12 @@
                                                                  Location ref,
                                                                  vixl32::Register obj,
                                                                  uint32_t offset,
-                                                                 Location temp,
+                                                                 Location maybe_temp,
                                                                  bool needs_null_check) {
   DCHECK_ALIGNED(offset, sizeof(mirror::HeapReference<mirror::Object>));
   vixl32::Register base = obj;
   if (offset >= kReferenceLoadMinFarOffset) {
-    base = RegisterFrom(temp);
+    base = RegisterFrom(maybe_temp);
     static_assert(IsPowerOfTwo(kReferenceLoadMinFarOffset), "Expecting a power of 2.");
     __ Add(base, obj, Operand(offset & ~(kReferenceLoadMinFarOffset - 1u)));
     offset &= (kReferenceLoadMinFarOffset - 1u);