Rather than embedding the ISR stub directly inside the function that
invokes IRQ_CONNECT(), stick all the generated stubs in the
.text.irqstubs section.
In this way, we make things easier to debug since the stub code isn't
mixed in with the "calling" function's assembly, and we no longer
need an instruction to jump over it.
Since these are now in their own section and not embedded inside an
unrelated init function, we unconditionally generate descriptive
symbol names for each stub based on the name of the handler and the
IRQ line.
Example for HPET timer on IRQ #2:
00100440 T _timer_int_handler <-- driver ISR
00100590 T _timer_int_handler_irq2_stub <-- generated stub
Change-Id: I49425aef7775edbca8ad7f61d2d4f9c41cb0d39d
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>