V3 and cross-compiler (AIX 4.3 64-bit mode)

[David Edelsohn]

	How is V3 configuration, specifically gen-num-limits, suppose to
work in the context of a cross-compiler?

	AIX 4.3 and above provides support for 64-bit applications.  All
of the rest of the toolchain and libraries exist on 32-bit systems; 64-bit
applications can be compiled and linked, but cannot be run.  GCC supports
that mode (-maix64) and it is one of the multilibs.

	V3 configuration wants to compile and run gen-num-limits for each
multilib.  A 32-bit AIX 4.3 system can do the former but not the latter.
GCC basically acts like a cross-compiler in that mode.

	For the AIX 4.3 multilibs, limitsMEMBERS.cc is (should be)
uniformly identical.  With Rainer's mknumeric_limits change, V3
configuration now does not create an incomplete file, butthe build stops. 

	How is one suppose to create limitsMEMBERS.cc for a
cross-compiler?  Is there any way to teach V3 configuration to re-use the
32-bit limitsMEMBERS.cc instead of failing to run a 64-bit application on
a 32-bit system?

Thanks, David