[lldb] Normalize paths in new test

The minidump-sysroot test I added in commit 20f8425 compares two paths
using a string comparison.  This causes the Windows buildbot to fail
because of mismatched forward slashes and backslashes.  Use
os.path.normcase to normalize before comparing.

Author: JosephTremoulet

lldb/test/API/functionalities/postmortem/minidump-new/TestMiniDumpNew.py

@@ -479,5 +479,6 @@ def test_minidump_sysroot(self):
         # Check that we loaded the module from the sysroot
         self.assertEqual(self.target.GetNumModules(), 1)
         module = self.target.GetModuleAtIndex(0)
-        spec = module.GetFileSpec()
-        self.assertEqual(spec.GetDirectory(), exe_dir)
+        spec_dir_norm = os.path.normcase(module.GetFileSpec().GetDirectory())
+        exe_dir_norm = os.path.normcase(exe_dir)
+        self.assertEqual(spec_dir_norm, exe_dir_norm)