Clean up global variables related to precompilation.

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 429631f3bf522699273bf0244cace61141de300c..d97368defc6c1205eb0d9f649293b8a810fc179d 100644
--- a/runtime/vm/flow_graph_compiler_arm.cc
+++ b/runtime/vm/flow_graph_compiler_arm.cc
@@ -29,6 +29,7 @@ DEFINE_FLAG(bool, unbox_mints, true, "Optimize 64-bit integer arithmetic.");
 DEFINE_FLAG(bool, unbox_doubles, true, "Optimize double arithmetic.");
 DECLARE_FLAG(bool, enable_simd_inline);
 DECLARE_FLAG(bool, use_megamorphic_stub);
+DECLARE_FLAG(bool, precompilation);
 
 
 void MegamorphicSlowPath::EmitNativeCode(FlowGraphCompiler* compiler) {
@@ -1124,7 +1125,7 @@ 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;
@@ -1288,7 +1289,7 @@ 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) {