ensure correct initialization order for local variables

ensure correct initialization order for local variables

section 10.5 requires that function definitions get initialized
at the beginning of the method. variable declarations do not
override the function definitions. assignments to variables
happen when they appear in the source code.

Also remove a duplicated intializations of variables to
undefined. This is already being done by initCallContext
or builtin_declare_vars, so no need to do it in the generated
code again.

Change-Id: I63805b97017f8676d57e0662073689e852b6ac23
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>