compiler: get existing parser using path

compiler/table.v

@@ -4,6 +4,7 @@
 
 module main
 
+import os
 import math
 import strings
 
@@ -862,7 +863,7 @@ fn (table &Table) qualify_module(mod string, file_path string) string {
 	for m in table.imports {
 		if m.contains('.') && m.contains(mod) {
 			m_parts := m.split('.')
-			m_path := m_parts.join('/')
+			m_path := m_parts.join(os.PathSeparator)
 			if mod == m_parts[m_parts.len-1] && file_path.contains(m_path) {
 				return m
 			}