This adds support for the new code points in the Extended Grapheme
Cluster algorithm. The algorithm itself has remained unchanged.
The width estimation still follows the rules of the Standard.
@cor3ntin filed
LWG3780 format's width estimation is too approximate and not forward compatible
to improve the estimate.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D134106
This changes makes it easier to update the Unicode data files used for
the Extended Graphme Clustering as added in D126971.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D129668