Fix performance regressions due to lazy initialization.

src/platform-openbsd.cc

Index: src/platform-openbsd.cc
diff --git a/src/platform-openbsd.cc b/src/platform-openbsd.cc
index b79cb71a50b2c82907b4e3580b0ea2a36b4beaff..6a06e3e53669b66680d718d16a04e548af6e6aa3 100644
--- a/src/platform-openbsd.cc
+++ b/src/platform-openbsd.cc
@@ -51,6 +51,7 @@
 
 #include "v8.h"
 
+#include "platform-posix.h"
 #include "platform.h"
 #include "v8threads.h"
 #include "vm-state-inl.h"
@@ -107,6 +108,13 @@ void OS::SetUp() {
 }
 
 
+void OS::PostSetUp() {
+  // Math functions depend on CPU features therefore they are initialized after
+  // CPU.
+  MathSetup();
+}
+
+
 uint64_t OS::CpuFeaturesImpliedByPlatform() {
   return 0;
 }