cc/gcc: remove duplicate code in core pass-1

Whatever the threading model (NPTL, LT...), we build the same
core pass-1 compiler, so there is no need to have a case-esac
construct.

Remove now mis-leading and incorect comment.

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

CT_EXPERIMENTAL=y

CT_LOCAL_TARBALLS_DIR="${HOME}/src"

CT_SAVE_TARBALLS=y

CT_LOG_EXTRA=y

CT_ARCH_s390=y

CT_KERNEL_linux=y

CT_KERNEL_V_2_6_31_14=y

CT_BINUTILS_V_2_20_1a=y

CT_CC_V_4_3_4=y

CT_CC_LANG_CXX=y

CT_LIBC_glibc=y

CT_LIBC_GLIBC_V_2_9=y

CT_GMP_V_4_3_2=y

CT_MPFR_V_2_4_2=y