codeparser: accept a name for better messages

- If a name is passed to the parser, prepend the messages with "while
  parsing <name>:". This gives a bit more context.
- Tweak the warning messages slightly (they had to be altered anyway to
  inject the variable being parsed).

Before:
  DEBUG: Warning: in call to 'bb.data.getVar': argument ''%s' % var' is \
         not a literal

After:
  DEBUG: while parsing emit_pkgdata, in call of bb.data.getVar, argument \
         ''%s' % var' is not a string literal

(Bitbake rev: 1060193ae4d54e667735dbff5d1d2be49a3f95c9)

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/data_smart.py

@@ -68,7 +68,7 @@ class VariableParse:
             code = match.group()[3:-1]
             codeobj = compile(code.strip(), self.varname or "<expansion>", "eval")
 
-            parser = bb.codeparser.PythonParser()
+            parser = bb.codeparser.PythonParser(self.varname)
             parser.parse_python(code)
             self.references |= parser.references
             self.execs |= parser.execs