fix stdio.h test to reflect removal of ::gets in c++14
fix stdio.h test to reflect removal of ::gets in c++14

git-svn-id: 756ef344af921d95d562d9e9f9389127a89a6314@215329 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx