Move SIGSEGV handler in Runtime and make ContextOutOfBoundsTest more robust

EMPER's Runtime now installs the SIGSEGV handler that checks if the
segmentation fault was caused by hitting the guard page. If the guard
page was hit, then the handler prints an error message.

Also make ContextOutOfBoundsTest more robust by not creating an
infinite recursion, which may be optmized out by the compiler.