Fixed windows bots that were failing because of PATH_MAX

As we only use PATH_MAX for an assert in a unit test that is supposed
to catch the random failures on the Swift CI bots, we might as well
just ifdef this assert out on Windows.

llvm-svn: 340652

lldb/unittests/Interpreter/TestCompletion.cpp

@@ -165,7 +165,9 @@ TEST_F(CompletionTest, DirCompletionAbsolute) {
   // for that directory, not items under it.
   // Sanity check that the path we complete on exists and isn't too long.
   ASSERT_TRUE(llvm::sys::fs::exists(BaseDir));
+#ifdef PATH_MAX
   ASSERT_LE(BaseDir.size(), static_cast<size_t>(PATH_MAX));
+#endif
   size_t Count =
       CommandCompletions::DiskDirectories(BaseDir, Results, Resolver);
   ASSERT_EQ(1u, Count);