VM: Support bootstrapping core libraries from Kernel binaries instead of source.

runtime/vm/flow_graph_compiler.cc

Index: runtime/vm/flow_graph_compiler.cc
diff --git a/runtime/vm/flow_graph_compiler.cc b/runtime/vm/flow_graph_compiler.cc
index 084579a1f813d44cf386a7d8780eed9c0f27d3c4..a22e4e44622b3e1dbdeda61bdec50068cced988b 100644
--- a/runtime/vm/flow_graph_compiler.cc
+++ b/runtime/vm/flow_graph_compiler.cc
@@ -84,6 +84,7 @@ static void PrecompilationModeHandler(bool value) {
     FATAL("Precompilation not supported on IA32");
 #endif
 
+#if !defined(DART_PRECOMPILED_RUNTIME)
     // Flags affecting compilation only:
     // There is no counter feedback in precompilation, so ignore the counter
     // when making inlining decisions.
@@ -97,6 +98,7 @@ static void PrecompilationModeHandler(bool value) {
     FLAG_inlining_caller_size_threshold = 1000;
     FLAG_inlining_constant_arguments_max_size_threshold = 100;
     FLAG_inlining_constant_arguments_min_size_threshold = 30;
+#endif
 
     FLAG_background_compilation = false;
     FLAG_fields_may_be_reset = true;