Cross Reference: /external/libcxx/test/std/strings/basic.string/string.modifiers/string_append

`Name`	`Date`	`Size`
Up to higher level directory
`initializer_list.pass.cpp`	22-Oct-2020	`854`
`iterator.pass.cpp`	22-Oct-2020	`9.5K`
`pointer.pass.cpp`	22-Oct-2020	`2.4K`
`pointer_size.pass.cpp`	22-Oct-2020	`3K`
`push_back.pass.cpp`	22-Oct-2020	`1.3K`
`size_char.pass.cpp`	22-Oct-2020	`1.9K`
`string.pass.cpp`	22-Oct-2020	`3.1K`
`string_size_size.pass.cpp`	22-Oct-2020	`4.1K`
`string_view.pass.cpp`	22-Oct-2020	`3.1K`
`T_size_size.pass.cpp`	22-Oct-2020	`5.7K`