Sometimes build systems may append options e.g. --sysroot etc. to CC
variable especially in cross-compile environments like yocto project
where CC varable is composed of cross-compiler name and some needed
options for it to work in a relocatable environment.

Therefore separate out the compiler name from rest of the options in CC,
then add the options via second argument to Popen() API
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Fangrui Song <maskray@google.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Keeping <john@metanate.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Link: https://lore.kernel.org/r/20221205025534.150006-1-raj.khem@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>