Mark __clear_and_shrink() as noexcept. This prevents the generation of a catch block and call to terminate in string's move assignment. Thanks to Howard for the 'catch'.
Mark __clear_and_shrink() as noexcept. This prevents the generation of a catch block and call to terminate in string's move assignment. Thanks to Howard for the 'catch'.

git-svn-id: 756ef344af921d95d562d9e9f9389127a89a6314@333435 91177308-0d34-0410-b5e6-96231b3b80d8

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