* commands/i386/pc/drivemap_int13h.S: Use LOCAL when possible.
Add 0 byte at the end not to have a symbol with empty target.
* mmap/i386/pc/mmap_helper.S: Likewise.
* genmk.rb: Ignore errors 2030 and 2050.
* kern/i386/pc/startup.S: Use LOCAL when possible.
Fix build with Apple's toolchain. Part 1
* commands/i386/pc/drivemap_int13h.S: use assembly-time constants
for long calls
* configure.ac: remove a leftover AC_MSG_RESULT
(CFLAGS): don't add -Wl,--defsym,___main=0x8100 when building with
Apple's toolchain
Absolute addressing through constant with Apple's cc
* kern/i386/pc/startup.S: Define necessary constants
and address through it when using ABS with Apple's CC
* boot/i386/pc/diskboot.S: likewise
* boot/i386/pc/boot.S: likewise
* boot/i386/pc/lnxboot.S: likewise
* boot/i386/pc/cdboot.S: likewise
* mmap/i386/pc/mmap_helper.S: likewise
* commands/i386/pc/drivemap_int13h.S: likewise
