[tlbuild] problem disabling luajit and luatex

[Nelson H. F. Beebe]

For TeX Live 2016 on Red Hat 5 IA-64 (Itanium), I added the suggested
extra flag to have

	--disable-luajittex --disable-luatex --disable-mfluajit

and started a fresh build.  It took one manual patch in texk/Makefile
to get past a failure point:

	% diff Makefile.org Makefile
	341c341
	< LIBS =  -lm
	---
	> LIBS = -lz -lm

I then did "make world -i -k" in the Work directory, and ended up with
367 executables, with the new binaries available from a link near the
top of this updated Web site:

	http://www.math.utah.edu/pub/texlive/

The binary distribution count is now 56.

The original luajit configuration failure looked like this:

	checking for _FILE_OFFSET_BITS value needed for large files... no
	checking for _LARGEFILE_SOURCE value needed for large files... no
	configure: error: Sorry, can not preprocess <lj_arch.h>
	=== configuring in luajit failed
	Makefile:898: recipe for target 'recurse' failed

The  lj_arch.h file has this block of architecture definitions:

	#define LUAJIT_ARCH_X86         1
	#define LUAJIT_ARCH_x86         1
	#define LUAJIT_ARCH_X64         2
	#define LUAJIT_ARCH_x64         2
	#define LUAJIT_ARCH_ARM         3
	#define LUAJIT_ARCH_arm         3
	#define LUAJIT_ARCH_ARM64       4
	#define LUAJIT_ARCH_arm64       4
	#define LUAJIT_ARCH_PPC         5
	#define LUAJIT_ARCH_ppc         5
	#define LUAJIT_ARCH_MIPS        6
	#define LUAJIT_ARCH_mips        6

The IA-64 (Itanium) platform is not among them.  C/C++ compilers on
that system define the symbols __ia64 and __ia64__.  It is normally
little-endian, like x86_64, but its register model is very different.
The lj_arch.h file has symbols that refer to register numbers, which
would normally be accessible only through __asm__() macros, so I
expect that it might be nontrivial to add IA-64 support. I do not
propose to investigate that question further.

-------------------------------------------------------------------------------
- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
- Department of Mathematics, 110 LCB    Internet e-mail: beebe at math.utah.edu  -
- 155 S 1400 E RM 233                       beebe at acm.org  beebe at computer.org -
- Salt Lake City, UT 84112-0090, USA    URL: http://www.math.utah.edu/~beebe/ -
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