Clean up global variables related to precompilation.

runtime/vm/flow_graph_compiler_arm64.cc

Index: runtime/vm/flow_graph_compiler_arm64.cc
diff --git a/runtime/vm/flow_graph_compiler_arm64.cc b/runtime/vm/flow_graph_compiler_arm64.cc
index 977010a2d22ea2d91d5f120c1ea230b311d6f74a..6f76a03c1944aa5df82c8a3accd3551c85110169 100644
--- a/runtime/vm/flow_graph_compiler_arm64.cc
+++ b/runtime/vm/flow_graph_compiler_arm64.cc
@@ -26,6 +26,7 @@ namespace dart {
 DEFINE_FLAG(bool, trap_on_deoptimization, false, "Trap on deoptimization.");
 DECLARE_FLAG(bool, enable_simd_inline);
 DECLARE_FLAG(bool, use_megamorphic_stub);
+DECLARE_FLAG(bool, precompilation);
 
 
 void MegamorphicSlowPath::EmitNativeCode(FlowGraphCompiler* compiler) {
@@ -1117,7 +1118,7 @@ void FlowGraphCompiler::CompileGraph() {
   ASSERT(assembler()->constant_pool_allowed());
   GenerateDeferredCode();
 
-  if (is_optimizing() && Compiler::allow_recompilation()) {
+  if (is_optimizing() && !FLAG_precompilation) {
     // Leave enough space for patching in case of lazy deoptimization from
     // deferred code.
     for (intptr_t i = 0;
@@ -1270,7 +1271,7 @@ void FlowGraphCompiler::EmitMegamorphicInstanceCall(
 
   RecordSafepoint(locs);
   const intptr_t deopt_id_after = Thread::ToDeoptAfter(deopt_id);
-  if (Compiler::always_optimize()) {
+  if (FLAG_precompilation) {
     // Megamorphic calls may occur in slow path stubs.
     // If valid use try_index argument.
     if (try_index == CatchClauseNode::kInvalidTryIndex) {