Fix some warnings and fix some simulator builds

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4688 42af7a65-404d-4744-a932-0658087f49c3

libxx/README.txt

@@ -7,11 +7,30 @@ embedded world, that is probably all that is necessary.  If you
 have a need for more extensive C++ support, the following libraries
 are recommended:
 
- - libstdc++	(part of GCC)
- - STLport	http://www.stlport.org/ 
- - uClibc++	http://cxx.uclibc.org/
+ - libstdc++  (part of GCC)
+ - STLport    http://www.stlport.org/ 
+ - uClibc++   http://cxx.uclibc.org/
 
 At present, only the following are supported here:
 
  - void *operator new(std::size_t nbytes);
- - void operator delete(void* ptr);
+ - void operator delete(void* ptr);
+ - void operator delete[](void *ptr);
+ - void __cxa_pure_virtual(void);
+ - int __aeabi_atexit(void* object, void (*destroyer)(void*), void *dso_handle);
+ 
+operator new
+------------
+
+  This operator should take a type of size_t.  But size_t has an unknown underlying
+  type.  In the nuttx sys/types.h header file, size_t is typed as uint32_t
+  (which is determined by architecture-specific logic).  But the C++
+  compiler may believe that size_t is of a different type resulting in
+  compilation errors in the operator.  Using the underlying integer type
+  instead of size_t seems to resolve the compilation issues. Need to
+  REVISIT this.
+
+  Once some C++ compilers, this will cause an error:
+
+    Problem:     "'operator new' takes size_t ('...') as first parameter"
+    Workaround:  Add -fpermissive to the compilation flags