bitbake: event/ast: Use better_exec instead of simple_exec

This improves the stacktraces dumped by bitbake when for example anonymous
python functions fail.

Also default to passing code strings to better_exec to match the behaviour of
simple_exec to aid the transition.

(Bitbake rev: 7e8205929ae953731a6854ea80b197847cff5771)

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

bitbake/lib/bb/utils.py

@@ -218,13 +218,15 @@ def better_compile(text, file, realfile, mode = "exec"):
 
         raise
 
-def better_exec(code, context, text, realfile = "<code>"):
+def better_exec(code, context, text = None, realfile = "<code>", data = None):
     """
     Similiar to better_compile, better_exec will
     print the lines that are responsible for the
     error.
     """
     import bb.parse
+    if not text:
+        text = code
     if not hasattr(code, "co_filename"):
         code = better_compile(code, realfile, realfile)
     try: