Clean up global variables related to precompilation.

runtime/vm/flow_graph_range_analysis.cc

Index: runtime/vm/flow_graph_range_analysis.cc
diff --git a/runtime/vm/flow_graph_range_analysis.cc b/runtime/vm/flow_graph_range_analysis.cc
index 16cf90c4e8c42c056ace9b3a55e5e15f3101f6b4..014b1969897de529a239e5353e53fd5aeb4d29b0 100644
--- a/runtime/vm/flow_graph_range_analysis.cc
+++ b/runtime/vm/flow_graph_range_analysis.cc
@@ -15,6 +15,7 @@ DEFINE_FLAG(bool, array_bounds_check_elimination, true,
 DEFINE_FLAG(bool, trace_range_analysis, false, "Trace range analysis progress");
 DEFINE_FLAG(bool, trace_integer_ir_selection, false,
     "Print integer IR selection optimization pass.");
+DECLARE_FLAG(bool, precompilation);
 DECLARE_FLAG(bool, trace_constant_propagation);
 
 // Quick access to the locally defined isolate() and zone() methods.
@@ -1534,7 +1535,7 @@ void RangeAnalysis::EliminateRedundantBoundsChecks() {
     // optimistic hoisting of checks possible)
     const bool try_generalization =
         function.allows_bounds_check_generalization() &&
-        !Compiler::always_optimize();
+        !FLAG_precompilation;
 
     BoundsCheckGeneralizer generalizer(this, flow_graph_);