usp10/tests: update test_ScriptStringXtoCP_CPtoX to test both rtl and ltr characters

[Aric Stewart]

On 10/10/28 13:47, Aric Stewart wrote:
> ---
>   dlls/usp10/tests/usp10.c |  157 ++++++++++++++++++++++++++++------------------
>   1 files changed, 97 insertions(+), 60 deletions(-)
>