Update V8 to r6190 as required by WebKit r75315

Change-Id: I0b2f598e4d8748df417ad350fc47a1c465ad1fef
diff --git a/src/platform-solaris.cc b/src/platform-solaris.cc
index f84e80d..04c25a9 100644
--- a/src/platform-solaris.cc
+++ b/src/platform-solaris.cc
@@ -401,6 +401,12 @@
 
 
 Thread::Thread() : ThreadHandle(ThreadHandle::INVALID) {
+  set_name("v8:<unknown>");
+}
+
+
+Thread::Thread(const char* name) : ThreadHandle(ThreadHandle::INVALID) {
+  set_name(name);
 }
 
 
@@ -420,6 +426,12 @@
 }
 
 
+void Thread::set_name(const char* name) {
+  strncpy(name_, name, sizeof(name_));
+  name_[sizeof(name_) - 1] = '\0';
+}
+
+
 void Thread::Start() {
   pthread_create(&thread_handle_data()->thread_, NULL, ThreadEntry, this);
   ASSERT(IsValid());