Now to detect a system that's LP64 we need to check a special define for
each architecture.  Now it's something like:

#if defined(__alpha__) || defined(__sparc_v9__)

or

#if defined(__alpha__) || (defined(__sparc__) && defined(__arch64__))

If we start having 64-bit POWER/PPC, 64-bit MIPs, or ia64, these checks
will quickly become unweildy.

I propose we add a new define to the gcc specs file to identify a 64-bit
target so we don't have to keep messing about with architecture specific
defines.

Alternatively we can change these to compare LONG_MAX to INT_MAX as
follows:

#if (LONG_MAX > INT_MAX)
	/* LP64 code */
#else
	/* ILP32 code */
#endif

However, this requires <sys/limits.h> and does not properly identify the
width of a pointer.

Eduardo Horvath