stringi_1.6.2

• [BACKWARD INCOMPATIBILITY] In stri_enc_list(),
  simplify now defaults to TRUE.

• [NEW FEATURE] #425: The outputs of stri_enc_list(), stri_locale_list(),
  stri_timezone_list(), and stri_trans_list() are now sorted.

• [NEW FEATURE] #428: In stri_flatten, na_empty=NA now omits missing values.

• [BUILD TIME] #431: Pre-4.9.0 GCC has ::max_align_t,
  but not std::max_align_t, added a (possible) workaround, see the INSTALL
  file.

• [BUGFIX] #429: stri_width() misclassified the width of certain
  code points (including grave accent, Eszett, etc.);
  General category Sk (Symbol, modifier) is no longer of width 0,
  UCHAR_EAST_ASIAN_WIDTH of U_EA_AMBIGUOUS is no longer of width 2.

• [BUGFIX] #354: ALTREP CHARSXPs were not copied, and thus could have been
  garbage collected in the so-called meanwhile (with thanks to @jimhester).