[libcxxabi] NFC: Fix trivial typos in comments

[kiszk]

rebase with master

[kiszk]

I do not have commit rights to the repository yet. Could someone commit this change if it is OK?

libcxxabi/src/CMakeLists.txt

     set(MERGE_ARCHIVES_LIBTOOL "--use-libtool" "--libtool" "${CMAKE_LIBTOOL}")
   endif()
 
-  # Merge the the libc++abi.a and libunwind.a into one.
+  # Merge the libc++abi.a and libunwind.a into one.
   if(LIBCXXABI_USE_LLVM_UNWINDER AND LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_STATIC_LIBRARY)
     add_custom_command(TARGET cxxabi_static POST_BUILD
       COMMAND ${PYTHON_EXECUTABLE} ${LIBCXXABI_LIBCXX_PATH}/utils/merge_archives.py

libcxxabi/test/test_demangle.pass.cpp

             std::free(demang);
             break;
         case 1:
-            std::cout << "not immplemented\n";
+            std::cout << "not implemented\n";
             break;
         }
         std::cout << '\n';