Split libc_debug.so into two .so modules loaded on demand from libc.so

This change is intended to eliminate need to replace libc.so with libc_debug.so in order to enablememory allocation debugging.
This is also the first step towards implementing extended memoryallocation debugging using emulator's capabilities in monitoring memory access.
diff --git a/libc/bionic/dlmalloc.h b/libc/bionic/dlmalloc.h
index e5f7d4a..1b642d2 100644
--- a/libc/bionic/dlmalloc.h
+++ b/libc/bionic/dlmalloc.h
@@ -1,14 +1,14 @@
 /*
   Default header file for malloc-2.8.x, written by Doug Lea
   and released to the public domain, as explained at
-  http://creativecommons.org/licenses/publicdomain. 
- 
+  http://creativecommons.org/licenses/publicdomain.
+
   last update: Mon Aug 15 08:55:52 2005  Doug Lea  (dl at gee)
 
   This header is for ANSI C/C++ only.  You can set any of
   the following #defines before including:
 
-  * If USE_DL_PREFIX is defined, it is assumed that malloc.c 
+  * If USE_DL_PREFIX is defined, it is assumed that malloc.c
     was also compiled with this option, so all routines
     have names starting with "dl".
 
@@ -34,7 +34,7 @@
 #if !ONLY_MSPACES
 
 /* Check an additional macro for the five primary functions */
-#if !defined(USE_DL_PREFIX) || !defined(MALLOC_LEAK_CHECK) 
+#if !defined(USE_DL_PREFIX)
 #define dlcalloc               calloc
 #define dlfree                 free
 #define dlmalloc               malloc