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)
1 This is a somewhat ordered TODO list:
5 - update versions for every tools...
7 - update and/or upgrade all samples
12 - update newlib (for enhanced bare metal)
13 - confirm existing implementation on targets other than AVR32
14 - try to make it generic, will help for uClibc++
18 - Cygwin target (needs newlib)
19 - so we can build toolchains that generate code for Windows/Cygwin
22 - so we can build toolchains that run natively under Windows/Cygwin
25 - so we can build toolchains that generate code for Windows/Win32
28 - so we can build toolchains that run natively under Windows/Win32
29 (without requiring Cygwin)
35 - check whether we can use newlib under uClinux (?)