perf python: split Clang options when invoking Popen

When passing a list to subprocess.Popen, each element maps to one argv
token. Current code bundles multiple Clang flags into a single element,
something like:

cmd = ['clang',
'--target=x86_64-linux-gnu -fintegrated-as -Wno-cast-function-type-mismatch',
'test-hello.c']

So Clang only sees one long, invalid option instead of separate flags,
as a result, the script cannot capture any log via PIPE.

Fix this by using shlex.split() to separate the string so each option
becomes its own argv element. The fixed list will be:

cmd = ['clang',
'--target=x86_64-linux-gnu',
'-fintegrated-as',
'-Wno-cast-function-type-mismatch',
'test-hello.c']

Fixes: 09e6f9f98370 ("perf python: Fix splitting CC into compiler and options")
Signed-off-by: Leo Yan <[e-mail]>
Reviewed-by: Ian Rogers <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Cc: Palmer Dabbelt <[e-mail]>
Cc: Albert Ou <[e-mail]>
Cc: Alexandre Ghiti <[e-mail]>
Cc: Nick Desaulniers <[e-mail]>
Cc: Justin Stitt <[e-mail]>
Cc: Bill Wendling <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Nathan Chancellor <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: Paul Walmsley <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/setup.py

···
 from os import getenv, path
 from subprocess import Popen, PIPE
 from re import sub
+import shlex
 
 cc = getenv("CC")
 assert cc, "Environment variable CC not set"
···
 src_feature_tests  = f'{srctree}/tools/build/feature'
 
 def clang_has_option(option):
-    cc_output = Popen([cc, cc_options + option, path.join(src_feature_tests, "test-hello.c") ], stderr=PIPE).stderr.readlines()
+    cmd = shlex.split(f"{cc} {cc_options} {option}")
+    cmd.append(path.join(src_feature_tests, "test-hello.c"))
+    cc_output = Popen(cmd, stderr=PIPE).stderr.readlines()
     return [o for o in cc_output if ((b"unknown argument" in o) or (b"is not supported" in o) or (b"unknown warning option" in o))] == [ ]
 
 if cc_is_clang: