VM: Store edge counters in one per-function array.

runtime/vm/intermediate_language_arm.cc

Index: runtime/vm/intermediate_language_arm.cc
diff --git a/runtime/vm/intermediate_language_arm.cc b/runtime/vm/intermediate_language_arm.cc
index 8fb50b4a9253b4085b747f5f10deab23b6fdf231..026d0ed938dd24e31d6e6318895c900dd38f3d84 100644
--- a/runtime/vm/intermediate_language_arm.cc
+++ b/runtime/vm/intermediate_language_arm.cc
@@ -6642,13 +6642,10 @@ LocationSummary* GotoInstr::MakeLocationSummary(Zone* zone,
 void GotoInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   if (!compiler->is_optimizing()) {
     if (FLAG_emit_edge_counters) {
-      compiler->EmitEdgeCounter();
+      compiler->EmitEdgeCounter(block()->preorder_number());
     }
     // Add a deoptimization descriptor for deoptimizing instructions that
-    // may be inserted before this instruction.  On ARM this descriptor
-    // points after the edge counter code so that we can reuse the same
-    // pattern matching code as at call sites, which matches backwards from
-    // the end of the pattern.
+    // may be inserted before this instruction.
     compiler->AddCurrentDescriptor(RawPcDescriptors::kDeopt,
                                    GetDeoptId(),
                                    Scanner::kNoSourcePos);