Squish: Limit suite_CCOM to Qt4 kits

Change-Id: I49016d432221f39bc525fa4a548968294f139976
Reviewed-by: Robert Loehning <robert.loehning@digia.com>
Squish: Fix detection of clang++ on Mac

Change-Id: I02f68f7942a3774c686e1482d275e22a6037af2a
Reviewed-by: Robert Loehning <robert.loehning@digia.com>
Squish: Avoid Squish crash in tst_rename_file on Mac

Change-Id: I51b16970504d85eed63cf0ddd7b0ff07b6226273
Reviewed-by: Robert Loehning <robert.loehning@digia.com>