cc: add options to differentiate the need for pass-1 and pass-2

In some cases, building the core pass-1 is unneeded, as the C library
will not try to build anything when installing headers, or sill not
install anything at all.

This is for example the case for newlib, wihch does not require a core
pass-1 since it builds nothing and installs no header.

This should also be the case for newer glibc-es with newer gcc-es,
which no longer require a core pass-1, since the circular dependency
glibc <-> gcc (about TLS?) has been resolved.

Reported-by: Trevor Woerner <trevor.woerner@linaro.org>
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_CPU="cortex-m3"

CT_ARCH_TUNE="cortex-m3"

CT_ARCH_FLOAT_SW=y

CT_ARCH_arm=y

# CT_ARCH_USE_MMU is not set

CT_ARCH_ARM_MODE_THUMB=y

CT_TARGET_VENDOR="bare_newlib_cortex_m3_nommu"

CT_ARCH_BINFMT_FLAT=y

CT_BINUTILS_V_2_19_1a=y

CT_CC_V_4_4_1=y

CT_CC_LANG_CXX=y

CT_LIBC_NEWLIB_V_1_18_0=y

CT_GMP_V_4_3_2=y

CT_MPFR_V_2_4_2=y

CT_PPL_V_0_10_2=y

CT_CLOOG_V_0_15_9=y