Use correct timezone information on Solaris

src/platform-solaris.cc

Index: src/platform-solaris.cc
diff --git a/src/platform-solaris.cc b/src/platform-solaris.cc
index 4248ea214faa9b7d2c23ec4527d668d4ce542e2c..07718fe50b99117a57071b90af30ac08273c2461 100644
--- a/src/platform-solaris.cc
+++ b/src/platform-solaris.cc
@@ -125,12 +125,8 @@ const char* OS::LocalTimezone(double time) {
 
 
 double OS::LocalTimeOffset() {
-  // On Solaris, struct tm does not contain a tm_gmtoff field.
-  time_t utc = time(NULL);
-  ASSERT(utc != -1);
-  struct tm* loc = localtime(&utc);
-  ASSERT(loc != NULL);
-  return static_cast<double>((mktime(loc) - utc) * msPerSecond);
+  tzset();
+  return -static_cast<double>(timezone * msPerSecond);
 }