Revert "[libc++] Use proper shell escaping in the executors"

This reverts f8452ddfcc, which broke some bots. I'll figure out what's
wrong and commit it again.

Cr-Mirrored-From: https://chromium.googlesource.com/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 7cb1aa9d9368274300cf472bc5532aa5a099da51
diff --git a/utils/run.py b/utils/run.py
index e9f9859..7cdf652 100644
--- a/utils/run.py
+++ b/utils/run.py
@@ -14,7 +14,6 @@
 
 import argparse
 import os
-import pipes
 import shutil
 import subprocess
 import sys
@@ -58,9 +57,8 @@
             else:
                 shutil.copy2(dep, args.execdir)
 
-        # Run the command line with the given environment in the execution directory.
-        commandLine = (pipes.quote(x) for x in remaining)
-        return subprocess.call(' '.join(commandLine), cwd=args.execdir, env=env, shell=True)
+        # Run the executable with the given environment in the execution directory.
+        return subprocess.call(' '.join(remaining), cwd=args.execdir, env=env, shell=True)
     finally:
         shutil.rmtree(args.execdir)