Revert "Revert "x86/x86-64: Avoid temporary for read barrier field load.""

Fixed the fault handler recognizing the TEST instruction and
fault address within the lock word. Added tests to 439-npe.

Bug: 29966877
Bug: 12687968
Test: Tested with ART_USE_READ_BARRIER=true on host.
Test: Tested with ART_USE_READ_BARRIER=true ART_HEAP_POISONING=true on host.

This reverts commit ccf15bca330f9a23337b1a4b5850f7fcc6c1bf15.

Change-Id: I8990def5f719c9205bf6e5fdba32027fa82bec50
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index 4e0e34c..44844ac 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -248,8 +248,7 @@
   void GenerateReferenceLoadTwoRegisters(HInstruction* instruction,
                                          Location out,
                                          Location obj,
-                                         uint32_t offset,
-                                         Location maybe_temp);
+                                         uint32_t offset);
   // Generate a GC root reference load:
   //
   //   root <- *address
@@ -427,7 +426,6 @@
                                              Location ref,
                                              CpuRegister obj,
                                              uint32_t offset,
-                                             Location temp,
                                              bool needs_null_check);
   // Fast path implementation of ReadBarrier::Barrier for a heap
   // reference array load when Baker's read barriers are used.
@@ -436,7 +434,6 @@
                                              CpuRegister obj,
                                              uint32_t data_offset,
                                              Location index,
-                                             Location temp,
                                              bool needs_null_check);
   // Factored implementation used by GenerateFieldLoadWithBakerReadBarrier
   // and GenerateArrayLoadWithBakerReadBarrier.
@@ -444,7 +441,6 @@
                                                  Location ref,
                                                  CpuRegister obj,
                                                  const Address& src,
-                                                 Location temp,
                                                  bool needs_null_check);
 
   // Generate a read barrier for a heap reference within `instruction`