Add code to mark functions rather than whole files as threadable.

Change-Id: Ie635fbbb96b8ade48501ec564fe135edc256537d
diff --git a/libs/rs/rsScriptC.h b/libs/rs/rsScriptC.h
index e5b5ba9..86a7ad3 100644
--- a/libs/rs/rsScriptC.h
+++ b/libs/rs/rsScriptC.h
@@ -89,6 +89,7 @@
     struct SymbolTable_t {
         const char * mName;
         void * mPtr;
+        bool threadable;
     };
     //static SymbolTable_t gSyms[];
     static const SymbolTable_t * lookupSymbol(const char *);