scripts/internal: cleanup build symlinks

The symlinks are needed only during the build process.
The final gcc will still search those dirs, but will also search
the standard lib/ dirs, so we can get rid of the symlinks.

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

 # Default test suite configuration

 # Default DejaGnu configuration

 DG_TOOLNAME = gcc

 DG_TARGET_HOSTNAME = 127.0.0.1

 DG_TARGET_USERNAME = root

 # Default tests

 DG_C_TESTS = 

 DG_CPP_TESTS =