tools/Directories.mk: Correct the path to the installed libcxx directory.

libs/libxx/Kconfig

@@ -36,9 +36,9 @@ config LIBCXX
 	bool "Build LLVM libcxx (must be installed)"
 	default n
 	---help---
-		If you have installed libcxx into the NuttX source try, then it can
+		If you have installed libcxx into the NuttX source tree, then it can
 		be built by selecting this option.  See the README.txt file in the
-		libcxx packet for information on installing libcxx.
+		libcxx package for information on installing libcxx.
 
 if LIBCXX
 

sched/group/group_create.c

@@ -203,6 +203,9 @@ int group_allocate(FAR struct task_tcb_s *tcb, uint8_t ttype)
   /* In a flat, single-heap build.  The stream list is allocated with the
    * group structure.  But in a kernel build with a kernel allocator, it
    * must be separately allocated using a user-space allocator.
+   *
+   * REVISIT:  Kernel threads should not require a stream allocation.  They
+   * should not be using C buffered I/O at all.
    */
 
   group->tg_streamlist = (FAR struct streamlist *)

tools/Directories.mk

@@ -74,7 +74,7 @@ endif
 #   configurations.
 
 ifeq ($(CONFIG_LIBCXX),y)
-LIBXX=libcxx
+LIBXX=libxx$(DELIM)libcxx
 else
 LIBXX=libxx
 endif