Runtime support for Script Group as single module

Also made two other cleanups:
- Changed KernelID/InvokeID into IDBase in class Closure
    Rather than having two fields in class Closure, one of type ScriptKernelID and
    the other InovkeID, use a single field of the common base class IDBase. Added a
    boolean field to indicate whether it is kernel or invoke, since -fno-rtti is on.
- Removed user pointer from CPU closure

Change-Id: I5553f86b2e58325f85649078d48685a38f12d62f
diff --git a/cpu_ref/rsCpuScript.h b/cpu_ref/rsCpuScript.h
index 44df8a9..aaaa2a2 100644
--- a/cpu_ref/rsCpuScript.h
+++ b/cpu_ref/rsCpuScript.h
@@ -87,6 +87,7 @@
     virtual void setGlobalBind(uint32_t slot, Allocation *data);
     virtual void setGlobalObj(uint32_t slot, ObjectBase *data);
 
+    const char* getFieldName(uint32_t slot) const;
 
     virtual ~RsdCpuScriptImpl();
     RsdCpuScriptImpl(RsdCpuReferenceImpl *ctx, const Script *s);