bitbake: data: Make expandKeys deterministic

At least in theory, the order the keys are expanded in can make
a difference, particularly if there is key overlap.

We also want to ensure that any underlying base key is processed
before any overridden version of that variable (FOO before FOO_x)
which helps the update_data removal code I've been testing.

(Bitbake rev: 863b6add24c211d64ba7931647084321f2d65889)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/data.py

@@ -159,7 +159,7 @@ def expandKeys(alterdata, readdata = None):
 
     # These two for loops are split for performance to maximise the
     # usefulness of the expand cache
-    for key in todolist:
+    for key in sorted(todolist):
         ekey = todolist[key]
         newval = alterdata.getVar(ekey, 0)
         if newval is not None: