VM: Fix bug in the new edge counter code on ARM and MIPS.

runtime/vm/flow_graph_compiler_arm.cc

Index: runtime/vm/flow_graph_compiler_arm.cc
diff --git a/runtime/vm/flow_graph_compiler_arm.cc b/runtime/vm/flow_graph_compiler_arm.cc
index c96c03662381807578def1dcc26b71addd2bcb42..8fa3431b1ad60bfa7cab403b1d665bd0e49f8122 100644
--- a/runtime/vm/flow_graph_compiler_arm.cc
+++ b/runtime/vm/flow_graph_compiler_arm.cc
@@ -1196,9 +1196,10 @@ void FlowGraphCompiler::EmitEdgeCounter(intptr_t edge_id) {
   bool old_use_far_branches = assembler_->use_far_branches();
   assembler_->set_use_far_branches(true);
 #endif  // DEBUG
-  __ ldr(IP, FieldAddress(R0, Array::element_offset(edge_id)));
-  __ add(IP, IP, Operand(Smi::RawValue(1)));
-  __ StoreIntoSmiField(FieldAddress(R0, Array::element_offset(edge_id)), IP);
+  __ LoadFieldFromOffset(kWord, R1, R0, Array::element_offset(edge_id));
+  __ add(R1, R1, Operand(Smi::RawValue(1)));
+  __ StoreIntoObjectNoBarrierOffset(
+      R0, Array::element_offset(edge_id), R1, Assembler::kOnlySmi);
 #if defined(DEBUG)
   assembler_->set_use_far_branches(old_use_far_branches);
 #endif  // DEBUG