Commit d6d3db0543 added more gcc version probes, exceeding the argument
limit of the SetupHostCommand macro, leading to failing GCC/LLVM tests
on OS X.
Extend the handled number of arguments to restore proper functionality.
Fixes FS#1470
Fixes d6d3db0543 ("build: Improve GCC version detection")
Signed-off-by: Jo-Philipp Wich <jo@mein.io>