Fuchsia: Make fuchsia_test use snapshots

runtime/vm/os_fuchsia.cc

Index: runtime/vm/os_fuchsia.cc
diff --git a/runtime/vm/os_fuchsia.cc b/runtime/vm/os_fuchsia.cc
index 2a813271b467d7d8d5be2a66149c99ad7d45caa7..b6343522633a5c30e7b7f50ee7db207ab7d731d2 100644
--- a/runtime/vm/os_fuchsia.cc
+++ b/runtime/vm/os_fuchsia.cc
@@ -167,19 +167,20 @@ void OS::DebugBreak() {
 
 
 char* OS::StrNDup(const char* s, intptr_t n) {
-  UNIMPLEMENTED();
-  return NULL;
+  return strndup(s, n);
 }
 
 
 intptr_t OS::StrNLen(const char* s, intptr_t n) {
-  UNIMPLEMENTED();
-  return 0;
+  return strnlen(s, n);
 }
 
 
 void OS::Print(const char* format, ...) {
-  UNIMPLEMENTED();
+  va_list args;
+  va_start(args, format);
+  VFPrint(stdout, format, args);
+  va_end(args);
 }