Fix test_bootstrap_without_em_config (#25754)

This tests was broken on systems where the python executable lives in
path that also contains clang executable.

We were remove PATH elements here, but we cannot remove the one that
contains the python executable otherwise the bootstrap script cannot run
at all.

Author: sbc100

test/test_sanity.py

@@ -8,6 +8,7 @@
 import re
 import shutil
 import stat
+import sys
 import time
 from pathlib import Path
 from subprocess import PIPE, STDOUT
@@ -822,9 +823,20 @@ def test_bootstrap_without_em_config(self):
     for e in ['LLVM_ROOT', 'EMSDK_NODE', 'EMSDK_PYTHON', 'EMSDK', 'EMSCRIPTEN', 'BINARYEN_ROOT', 'EMCC_SKIP_SANITY_CHECK', 'EM_CONFIG']:
       env.pop(e, None)
 
+    python_path = os.path.normpath(os.path.dirname(sys.executable))
+
     # Remove from PATH every directory that contains clang.exe so that bootstrap.py cannot
     # accidentally succeed by virtue of locating tools in PATH.
-    new_path = [d for d in env['PATH'].split(os.pathsep) if not os.path.isfile(os.path.join(d, utils.exe_suffix('clang')))]
+    def ignore_path(p):
+      clang_bin = utils.exe_suffix('clang')
+      # We cannot ignore a path element that contains the python executable itself, otherwise
+      # the bootstrap script will fail
+      if os.path.isfile(os.path.join(p, clang_bin)) and os.path.normpath(p) != python_path:
+        return True
+      return False
+
+    old_path = env['PATH'].split(os.pathsep)
+    new_path = [d for d in old_path if not ignore_path(d)]
     env['PATH'] = os.pathsep.join(new_path)
 
     # Running bootstrap.py should not fail