comptools: do not force build of make-3.81 unless really needed

On systems with make-3.82, we forcibly force the build and the use
of make-3.81

But some newer tools break when building with make-3.81. For example,
eglibc-3.18 breaks.

Introduce a new blind options that tools may select if they require
make-3.81. If the system does not have make-3.81, and this option is
selected, then we force the build of make-3.81. Otherwise, we leave
it to the user to decide on his own.

Note that no component selects this option for now. It will come in
later patches as we find them.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

diff -ru ltrace-0.5.3.orig/sysdeps/linux-gnu/Makefile ltrace-0.5.3/sysdeps/linux-gnu/Makefile

--- ltrace-0.5.3.orig/sysdeps/linux-gnu/Makefile	2009-07-25 17:13:02.000000000 +0200

+++ ltrace-0.5.3/sysdeps/linux-gnu/Makefile	2010-01-01 22:20:45.000000000 +0100

@@ -2,6 +2,7 @@

 				-e s/i.86/i386/ \

 				-e s/sun4u/sparc64/ \

 				-e s/sparc64/sparc/ \

+				-e s/alpha.*/alpha/ \

 				-e s/arm.*/arm/ \

 				-e s/sa110/arm/ \

 				-e s/ppc64/ppc/ \