Retrieve detailed location information when profiling signal handlers

Use the Functions associated with signal handlers to find out
which exact code is being executed.

Task-number: QTCREATORBUG-11100
Change-Id: Idfae9d188b17977b55f551e6fe766042fe24e786
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Parse source location for signal handling functions

Previously the source location of signal handlers was always line 0 and
column 0. This poses problems when trying to extract meaningful
profiling information. The change assigns the source location of the
statement declaring the function as the function's source location.

Task-number: QTCREATORBUG-11100
Change-Id: I4bb8682b35147a7cfe4ecec342d4a00623bb1e0d
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>