Mark test as a long-test

Differential Revision: https://reviews.llvm.org/D38452



git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@315570 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/input.output/stream.buffers/streambuf/streambuf.protected/streambuf.put.area/pbump2gig.pass.cpp

@@ -13,6 +13,8 @@
 // class basic_streambuf;
 
 // void pbump(int n);
+//
+// REQUIRES: long_tests
 
 #include <sstream>
 #include <cassert>