Fix performance regressions due to lazy initialization.

src/platform-win32.cc

Index: src/platform-win32.cc
diff --git a/src/platform-win32.cc b/src/platform-win32.cc
index 12cd610a3420c834d98efeea59f41ed59ebdbf33..dbd8eded8fae91c3aff3b7a5f6fe5ff0e03c5b6a 100644
--- a/src/platform-win32.cc
+++ b/src/platform-win32.cc
@@ -167,7 +167,6 @@ void OS::MemCopy(void* dest, const void* src, size_t size) {
 #ifdef _WIN64
 typedef double (*ModuloFunction)(double, double);
 static ModuloFunction modulo_function = NULL;
-V8_DECLARE_ONCE(modulo_function_init_once);
 // Defined in codegen-x64.cc.
 ModuloFunction CreateModuloFunction();
 
@@ -176,7 +175,6 @@ void init_modulo_function() {
 }
 
 double modulo(double x, double y) {
-  CallOnce(&modulo_function_init_once, &init_modulo_function);
   // Note: here we rely on dependent reads being ordered. This is true
   // on all architectures we currently support.
   return (*modulo_function)(x, y);
@@ -199,13 +197,10 @@ double modulo(double x, double y) {
 
 #define UNARY_MATH_FUNCTION(name, generator)             \
 static UnaryMathFunction fast_##name##_function = NULL;  \
-V8_DECLARE_ONCE(fast_##name##_init_once);                \
 void init_fast_##name##_function() {                     \
   fast_##name##_function = generator;                    \
 }                                                        \
 double fast_##name(double x) {                           \
-  CallOnce(&fast_##name##_init_once,                     \
-           &init_fast_##name##_function);                \
   return (*fast_##name##_function)(x);                   \
 }
 
@@ -218,6 +213,16 @@ UNARY_MATH_FUNCTION(sqrt, CreateSqrtFunction())
 #undef MATH_FUNCTION
 
 
+void MathSetup() {
+  init_modulo_function();
+  init_fast_sin_function();
+  init_fast_cos_function();
+  init_fast_tan_function();
+  init_fast_log_function();
+  init_fast_sqrt_function();
+}
+
+
 // ----------------------------------------------------------------------------
 // The Time class represents time on win32. A timestamp is represented as
 // a 64-bit integer in 100 nanoseconds since January 1, 1601 (UTC). JavaScript