Add the source position to variables if they are parameters.

Collect type information for parameters and return values. 
Index the types by their corresponding source position. For the
types of return values, use the function end as source position.


Sample output for a function with 2 parameters (at source
position 252 and 258, and function end at 443)
*************
Function: testFunction
252:
Object
number
string
number
258:
undefined
boolean
undefined
undefined
443:
Object
number
string
number
*************



BUG=v8:5933

Change-Id: I3b8749afcac706c1834146abf1b5b4a3fd130fb6
Reviewed-on: https://chromium-review.googlesource.com/461919Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Franziska Hinkelmann <franzih@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44299}