[lldb][test] Fix ThreadStepUntilAPI.py

After #167359 / 95db31e.

A fix was attempted in #167423 but was not quite enough.

From what I could understand, in v1 format you have to specify
all the basic blocks. Where before !call_me implied they were all
cold (I think, very shaky understanding here).

For this test we want to see blocks like call_me/foo/call_me.
So adding a line for block 1 fixes the tests.

It could produce more blocks at some point but I think as long
as foo is within two of them, it'll be fine.

Author: DavidSpickett

lldb/test/API/functionalities/thread/step_until/function.list

@@ -1,3 +1,4 @@
 v1
 f call_me
 c 0
+c 1