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>
1 reporter_name="unknown"
2 reporter_url="http://iphonelinux.org/index.php/Glibc_toolchain_using_crosstool-NG"
3 reporter_comment="An (experimental) toolchain targeting the Apple's iPhone."