Clang-Format: recombine string literals

Question

Is there a way to get clang-format to turn this:

function_name("a very very "                | <-- column limit
              "very very "                  |
              "long string");               |

into this:

function_name("a very very very very long"  |
              " string");                   |

It will happily break string literals over the limit, but I can't seem to get it to recombine.