[libcxx] [test] Fix comment typos, strip trailing whitespace.

No functional change, no code review.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292434 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/memory/unique.ptr/unique.ptr.single/unique.ptr.single.ctor/default.pass.cpp

@@ -20,7 +20,7 @@
 //
 // Plan
 //  1 Default construct unique_ptr's with various deleter types (C-1)
-//  2 Default construct a unique_ptr with a incomplete element_type and
+//  2 Default construct a unique_ptr with an incomplete element_type and
 //    various deleter types (C-1,2)
 
 #include <memory>

test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp

@@ -84,12 +84,12 @@ int main()
         T* ptr = new T;
         std::shared_ptr<T> s(ptr);
         {
-            // Don't re-initialize the "enabled_shared_from_this" base
+            // Don't re-initialize the "enable_shared_from_this" base
             // because it already references a non-expired shared_ptr.
             std::shared_ptr<T> s2(ptr, &nullDeleter);
         }
 #if TEST_STD_VER > 14
-        // The enabled_shared_from_this base should still be referencing
+        // The enable_shared_from_this base should still be referencing
         // the original shared_ptr.
         assert(!ptr->weak_from_this().expired());
 #endif