Add a write barrier elimination pass
We can eliminate redundant write barriers as we don't need several
for the same receiver. For example:
```
MyObject o;
o.inner_obj = io;
o.inner_obj2 = io2;
o.inner_obj3 = io3;
```
We can keep the write barrier for `inner_obj` and remove the other
two.
Note that we cannot perform this optimization across
invokes, suspend check, or instructions that can throw.
Local improvements (pixel 5, speed compile):
* System server: -280KB (-0.56%)
* SystemUIGoogle: -330KB (-1.16%)
* AGSA: -3876KB (-1.19%)
Bug: 260843353
Fixes: 260843353
Change-Id: Ibf98efbe891ee00e46125853c3e97ae30aa3ff30
diff --git a/compiler/optimizing/optimizing_compiler_stats.h b/compiler/optimizing/optimizing_compiler_stats.h
index 100441a..698a147 100644
--- a/compiler/optimizing/optimizing_compiler_stats.h
+++ b/compiler/optimizing/optimizing_compiler_stats.h
@@ -118,6 +118,8 @@
kConstructorFenceRemovedLSE,
kConstructorFenceRemovedPFRA,
kConstructorFenceRemovedCFRE,
+ kPossibleWriteBarrier,
+ kRemovedWriteBarrier,
kBitstringTypeCheck,
kJitOutOfMemoryForCommit,
kFullLSEAllocationRemoved,