scripts, cc/gcc: do not fail on existing symlinks or build.log

If the user builds a toolchain over an existing one, so, without removing
CT_PREFIX_DIR, the build fails as the symlinks already exist, as does the
build.log.

This can also happen (for build.log) if the user first ran in download-
or extract-only.

Patch (with no SoB) originally from:
Phil Wilshire <phil.wilshire@overturenetworks.com>

Modified by me as it did not apply cleanly.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from 1ebc2248cc60230cd53ff94ae8f8f1e3261461a3)

diff -durN glibc-cvs-2.9.orig/misc/syslog.c glibc-cvs-2.9/misc/syslog.c

--- glibc-cvs-2.9.orig/misc/syslog.c	2009-06-01 10:16:50.000000000 +0200

+++ glibc-cvs-2.9/misc/syslog.c	2009-06-01 10:17:20.000000000 +0200

@@ -152,7 +152,7 @@

 #define	INTERNALLOG	LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID

 	/* Check for invalid bits. */

 	if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {

-		syslog(INTERNALLOG,

+		__syslog(INTERNALLOG,

 		    "syslog: unknown facility/priority: %x", pri);

 		pri &= LOG_PRIMASK|LOG_FACMASK;

 	}