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

`Name`	`Date`	`Size`
Up to higher level directory
`char.pass.cpp`	06-Dec-2016	`1.2K`
`initializer_list.pass.cpp`	06-Dec-2016	`926`
`pointer.pass.cpp`	06-Dec-2016	`2.8K`
`string.pass.cpp`	06-Dec-2016	`2.9K`