Create function variables using the data produced by the pre-scanner. (#3199)

The pre-scanner now is able to track all variable declarations and produces a compressed
stream which store this data for each function and catch block. When a function or
catch block is parsed, this information is decoded and the appropriate variables are
created. Furthermore a stack scope is created which contains the currently available
local variables and their register or literal index.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

tests/debugger/do_variables.expected

@@ -34,8 +34,8 @@ level | type
 2     | global  
 (jerry-debugger) variables 0
 name | type      | value     
-n    | Number    | 9         
 b    | undefined | undefined 
+n    | Number    | 9         
 (jerry-debugger) variables 1
 name | type   | value 
 x    | Number | 3