Add a basic implementation of the reduce kernel API to the CPU
reference implementation.

Bug: 22631253

For now, this just runs a serial reduction on one thread.

Change-Id: I34c96d24bb6f44274de72bb53160abcf79d143b0
diff --git a/rsScriptIntrinsic.cpp b/rsScriptIntrinsic.cpp
index 3896586..223e93b 100644
--- a/rsScriptIntrinsic.cpp
+++ b/rsScriptIntrinsic.cpp
@@ -68,6 +68,11 @@
                                               aout, usr, usrBytes, sc);
 }
 
+void ScriptIntrinsic::runReduce(Context *rsc, uint32_t slot, const Allocation *ain,
+                                Allocation *aout, const RsScriptCall *sc) {
+}
+
+
 void ScriptIntrinsic::Invoke(Context *rsc, uint32_t slot, const void *data, size_t len) {
 }