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 This is a somewhat ordered TODO list:
5 - update versions for every tools...
7 - update and/or upgrade all samples
12 - update newlib (for enhanced bare metal)
13 - confirm existing implementation on targets other than AVR32
14 - try to make it generic, will help for uClibc++
18 - Cygwin target (needs newlib)
19 - so we can build toolchains that generate code for Windows/Cygwin
22 - so we can build toolchains that run natively under Windows/Cygwin
25 - so we can build toolchains that generate code for Windows/Win32
28 - so we can build toolchains that run natively under Windows/Win32
29 (without requiring Cygwin)
35 - check whether we can use newlib under uClinux (?)