Mark LWG issues #2075 and #2142 as complete. 2142 was a change to the standard
to remove redundant wording, which required no changes to libc++. 2075 was a 
rewrite of the requirements for forward progress, and again, requires no changes
to the library.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@204724 91177308-0d34-0410-b5e6-96231b3b80d8