Use stdint types in coff internal_auxent

Use stdint types in coff internal_auxent

long is a poor choice of type to store 32-bit values read from
objects files by H_GET_32.  H_GET_32 doesn't sign extend so tests like
that in gdb/coffread.c for "negative" values won't work if long is
larger than 32 bits.  If long is 32-bit then code needs to be careful
to not accidentally index negative array elements.  (I'd rather see a
segfault on an unmapped 4G array index than silently reading bogus
data.)  long is also a poor choice for x_sect.s_scnlen, which might
have 64-bit values.  It's better to use unsigned exact width types to
avoid surprises.

I decided to change the field names too, which makes most of this
patch simply renaming.  Besides that there are a few places where
casts are no longer needed, and where printf format strings or tests
need adjusting.

include/
	* coff/internal.h (union internal_auxent): Use unsigned stdint
	types.  Rename l fields to u32 and u64 as appropriate.
bfd/
	* coff-bfd.c,
	* coff-rs6000.c,
	* coff64-rs6000.c,
	* coffcode.h,
	* coffgen.c,
	* cofflink.c,
	* coffswap.h,
	* peXXigen.c,
	* xcofflink.c: Adjust to suit internal_auxent changes.
binutils/
	* rdcoff.c: Adjust to suit internal_auxent changes.
gas/
	* config/obj-coff.h,
	* config/tc-ppc.c: Adjust to suit internal_auxent changes.
gdb/
	* coffread.c,
	* xcoffread.c: Adjust to suit internal_auxent changes.
ld/
	* pe-dll.c: Adjust to suit internal_auxent changes.