Remove dead code before reg alloc in testing

Change-Id: I904d41fe7242266a7c63c30a6cff03e4ab760faa
diff --git a/src/main/java/com/android/tools/r8/ir/conversion/IRConverter.java b/src/main/java/com/android/tools/r8/ir/conversion/IRConverter.java
index f7b9ce0..b1b6e81 100644
--- a/src/main/java/com/android/tools/r8/ir/conversion/IRConverter.java
+++ b/src/main/java/com/android/tools/r8/ir/conversion/IRConverter.java
@@ -931,8 +931,9 @@
       Log.debug(getClass(), "Initial (SSA) flow graph for %s:\n%s", method.toSourceString(), code);
     }
     assert code.isConsistentSSA();
-    code.traceBlocks();
     Timing timing = Timing.empty();
+    deadCodeRemover.run(code, timing);
+    code.traceBlocks();
     RegisterAllocator registerAllocator = performRegisterAllocation(code, method, timing);
     method.setCode(code, registerAllocator, appView);
     if (Log.ENABLED) {