Refactors CPU feature detection.

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
===================================================================
--- runtime/vm/flow_graph_optimizer.cc	(revision 31745)
+++ runtime/vm/flow_graph_optimizer.cc	(working copy)
@@ -6,6 +6,7 @@
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
+#include "vm/cpu.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ -52,7 +53,7 @@
 #if defined(TARGET_ARCH_MIPS)
   return false;
 #elif defined(TARGET_ARCH_ARM)
-  return CPUFeatures::neon_supported() && FLAG_enable_simd_inline;
+  return TargetCPUFeatures::neon_supported() && FLAG_enable_simd_inline;
 #endif
   return FLAG_enable_simd_inline;
 }
@@ -2555,7 +2556,7 @@
       case MethodRecognizer::kDoubleTruncate:
       case MethodRecognizer::kDoubleFloor:
       case MethodRecognizer::kDoubleCeil:
-        if (!CPUFeatures::double_truncate_round_supported()) {
+        if (!TargetCPUFeatures::double_truncate_round_supported()) {
           ReplaceWithMathCFunction(call, recognized_kind);
         } else {
           AddReceiverCheck(call);