Second half (map/multimap) of N3657

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@188320 91177308-0d34-0410-b5e6-96231b3b80d8
Update for N3657 and issue 2010

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@188321 91177308-0d34-0410-b5e6-96231b3b80d8
Eradicate tabs

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@188322 91177308-0d34-0410-b5e6-96231b3b80d8