x86: 32 bit: interrupt stub consistency with 64 bit

Don't generate interrupt stubs for interrupt vectors below
FIRST_EXTERNAL_VECTOR, and make the table of interrupt vectors
(interrupt[]) __initconst.  Both of these changes both conserve memory
and improve consistency with 64 bits.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
4 files changed