Update documentation and add deprecate attribute.

Change-Id: I4a73b739789cedeba1cf7e64be11aaaa09a9474b
diff --git a/README.rst b/README.rst
index 98381e6..cf40138 100644
--- a/README.rst
+++ b/README.rst
@@ -94,7 +94,9 @@
 
 * **bccLinkBC** - Set the library bitcode for linking
 
-* **bccPrepareExecutable** - Create the in-memory executable by either
+* **bccPrepareExecutable** - *deprecated* - Use bccPrepareExecutableEx instead
+
+* **bccPrepareExecutableEx** - Create the in-memory executable by either
   just-in-time compilation or cache loading
 
 * **bccGetFuncAddr** - Get the entry address of the function