configure: use def_bool for available features

It's one line shorter, and easier to read.

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

debug/ltrace: Fix HOST_OS and ar

HOST_OS really is the target OS. Allow setting it for configure
via an environment variable.
libltrace.a should have an index:
Allow ar to be set as an environment variable, and generate
an index in this lib.

Reported-by: "Guylhem Aznar" <crossgcc@guylhem.net>
Signed-off-by: "Titus von Boxberg" <titus@v9g.de>

debug/gdb: correct compilation error when stpcpy is a define

On OSX stpcpy is a define which is not recognized by gdb's configure.
This results in a compilation error.

Reported-by: "Guylhem Aznar" <crossgcc@guylhem.net>
Signed-off-by: "Titus von Boxberg" <titus@v9g.de>

docs: Document usage with Xcode 4.1

With Xcode 4.1 'gcc' is symlinked llvm-gcc-4.2 which cannot bootstrap
other gccs.
See http://llvm.org/bugs/show_bug.cgi?id=9571

On my machine the faulty gcc is
gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2335.15.00)

Document a workaround.

Signed-off-by: "Titus von Boxberg" <titus@v9g.de>

libc/uClibc: portability fixes to install_headers

Add patch files for uClibc-0.9.30:
extra/scripts/install_headers.sh: find must be called with path.
extra/scripts/unifdef.c: getline is declared in <stdio.h>, use different name.

Reported-by: "Guylhem Aznar" <crossgcc@guylhem.net>
Reported-by: "Titus von Boxberg" <titus@v9g.de>
Signed-off-by: "Titus von Boxberg" <titus@v9g.de>

configure: require libtoolize, create wrapper to it

libtoolize must be checked_for and there needs to be a wrapper
that points to GNU libtoolize since that may be installed
as glibtoolize.
This fixes a problem with building Cloog/PPL that was

Reported-by: "Pierrick Brossin" <pierrick@bs-network.net>
Signed-off-by: "Titus von Boxberg" <titus@v9g.de>

configure: fix --with-prog=[...]

check_for didn't set variable 'where' when the path to a prog
was passed manually "(cached)".

Signed-off-by: "Titus von Boxberg" <titus@v9g.de>

complibs/libelf: use target ranlib

For portability, the right ranlib for the target must be passed to
libelf's configure.

Signed-off-by: "Titus von Boxberg" <titus@v9g.de>

configure: recognise and handle --program-transform-name

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

configure: recognise and handle --program-suffix

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