Revert "Disable write-barrier elimination pass"

This reverts commit 5a3271d7caafefd10a20f5a5db09d2c178838b76.

Reason for revert:
This CL has two fixes (codegen not doing a null check if a write
barrier is being relied on, and codegen not recomputing
skipping write barriers), regression tests, a new
runtime check which runs in debug mode for the CC GC to ensure
that the card table is set correctly for skipped write barriers,
and new compile time (graph checker) tests to ensure graph
consistency.

This patchset updates the WriteBarrierKind to be
{emit being relied on, emit not being relied on, dont emit},
which leaves the null check skip implementation to codegen.

Test 2247- is removed from knownfailures.json but still skipped
in MTS due to SLO requirements.

Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Bug: 301833859
Bug: 310755375
Bug: 260843353
Change-Id: I025597e284b2765986e2091538680ee629fb5ae7

1 files changed, 5 insertions, 0 deletions

diff --git a/compiler/optimizing/graph_checker.h b/compiler/optimizing/graph_checker.h
index 38e2d7ced9..5704bcec1a 100644
--- a/compiler/optimizing/graph_checker.h
+++ b/compiler/optimizing/graph_checker.h
@@ -59,6 +59,8 @@ class GraphChecker : public HGraphDelegateVisitor {
   void VisitPhi(HPhi* phi) override;
 
   void VisitArraySet(HArraySet* instruction) override;
+  void VisitInstanceFieldSet(HInstanceFieldSet* instruction) override;
+  void VisitStaticFieldSet(HStaticFieldSet* instruction) override;
   void VisitBinaryOperation(HBinaryOperation* op) override;
   void VisitBooleanNot(HBooleanNot* instruction) override;
   void VisitBoundType(HBoundType* instruction) override;
@@ -93,6 +95,9 @@ class GraphChecker : public HGraphDelegateVisitor {
   void HandleLoop(HBasicBlock* loop_header);
   void HandleBooleanInput(HInstruction* instruction, size_t input_index);
 
+  template <typename GetWriteBarrierKind>
+  void CheckWriteBarrier(HInstruction* instruction, GetWriteBarrierKind&& get_write_barrier_kind);
+
   // Was the last visit of the graph valid?
   bool IsValid() const {
     return errors_.empty();