Scope label names (for goto) to their functions

Seems some assemblers don't support local labels via .Lxyz
Fixed goto-label code, simplified backend jmp code
Only merge function prototypes if both are functions

Error handling is done later
__attribute__ arguments may be constant expressions
Allow inline with structs - e.g. function return
Fixed verbose passing to check/test scripts
Set $above to zero if no "^" is given
Normalise timeout's exit code (256 == 0)