cc/gcc: Apply CT_CC_GCC_DISABLE_PCH to do_cc_core.
Otherwise, users have to input --disable-libstdcxx-pch option
when building bare-metal CANADIAN C++ compiler.
Reviewed-by: Michael Hope
Signed-off-by: Zhenqiang Chen <zhenqiang.chen@linaro.org>
(transplanted from e3e1c9d45bddfbfb433ee9d583faf42fa31f50c0)
1 --- gcc-4.0.0/libstdc++-v3/include/c_std/std_cstdio.h-orig 2005-04-29 00:08:41.000000000 -0500
2 +++ gcc-4.0.0/libstdc++-v3/include/c_std/std_cstdio.h 2005-04-29 00:08:45.000000000 -0500
8 +#if _GLIBCXX_USE_C99 || defined(__UCLIBC__)