[libc++] Mark LWG3317 as complete in LLVM 16 (#110757)

This was fixed in 719c3dc and landed in LLVM 16.

Closes #100429

Author: ldionne

libcxx/docs/Status/Cxx20Issues.csv

@@ -239,7 +239,7 @@
 "`LWG3314 <https://wg21.link/LWG3314>`__","Is stream insertion behavior locale dependent when ``Period::type``\  is ``micro``\ ?","2020-02 (Prague)","|Complete|","16.0",""
 "`LWG3315 <https://wg21.link/LWG3315>`__","LWG3315: Correct Allocator Default Behavior","2020-02 (Prague)","|Complete|","",""
 "`LWG3316 <https://wg21.link/LWG3316>`__","Correctly define epoch for ``utc_clock``\  / ``utc_timepoint``\ ","2020-02 (Prague)","","",""
-"`LWG3317 <https://wg21.link/LWG3317>`__","Incorrect ``operator<<``\  for floating-point durations","2020-02 (Prague)","","",""
+"`LWG3317 <https://wg21.link/LWG3317>`__","Incorrect ``operator<<``\  for floating-point durations","2020-02 (Prague)","|Complete|","16.0",""
 "`LWG3318 <https://wg21.link/LWG3318>`__","Clarify whether clocks can represent time before their epoch","2020-02 (Prague)","","",""
 "`LWG3319 <https://wg21.link/LWG3319>`__","Properly reference specification of IANA time zone database","2020-02 (Prague)","|Nothing To Do|","",""
 "`LWG3320 <https://wg21.link/LWG3320>`__","``span::cbegin/cend``\  methods produce different results than ``std::[ranges::]cbegin/cend``\ ","2020-02 (Prague)","|Complete|","",""