cc/gcc: speed up the build a little bit

Even if the current process is highly parallel, crosstool-NG spends most
of its time in single-job steps on fast machines (with a 12-CPU system,
I approximate the parallel vs. non-parallel time to be in the order os
1 to 3; that is crostool-NG spends two-thirds of its time running
non-parallel jobs).

Some steps to build gcc can be paralleled, gaining a litle bit of time
on the whole compilation.

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

--- uClibc-0.9.30.orig/extra/scripts/install_headers.sh	2008-10-10 15:50:38.000000000 +0200

+++ uClibc-0.9.30/extra/scripts/install_headers.sh	2011-08-21 09:49:03.000000000 +0200

@@ -33,7 +33,7 @@

 (

 # We must cd, or else we'll prepend "$1" to filenames!

 cd "$1" || exit 1

-find ! -name '.' -a ! -path '*/.*' | sed -e 's/^\.\///' -e '/^config\//d' \

+find . ! -name '.' -a ! -path '*/.*' | sed -e 's/^\.\///' -e '/^config\//d' \

 	-e '/^config$/d'

 ) | \

 (