Consider passing `outer` unrecycled and recycle return value of `.name_spec`

[lionel-]

This is a bit surprising and causes bugs (see tidyverse/dplyr#5224):

vec_c(foo = c(1, 2), .name_spec = ~ print(list(.x, .y)))
#> [[1]]
#> [1] "foo" "foo"
#>
#> [[2]]
#> [1] 1 2