.1+.2 fails -- the fix to https://github.com/joyent/node/issues/4268 was not complete

    .1+.2

The original fix in https://github.com/bnoordhuis/node/commit/b6e989759bfcfdc00d9d4b5a3b32d31ea29838c0 only worked for a single float (and not for an arbitrary expression).