Fix lld command on Windows for many tests.

llvm-svn: 233416
diff --git a/lldb/test/api/multiple-debuggers/TestMultipleDebuggers.py b/lldb/test/api/multiple-debuggers/TestMultipleDebuggers.py
index c88c1ab..d238692 100644
--- a/lldb/test/api/multiple-debuggers/TestMultipleDebuggers.py
+++ b/lldb/test/api/multiple-debuggers/TestMultipleDebuggers.py
@@ -14,6 +14,7 @@
     def setUp(self):
         TestBase.setUp(self)
         self.lib_dir = os.environ["LLDB_LIB_DIR"]
+        self.implib_dir = os.environ["LLDB_IMPLIB_DIR"]
 
     @skipIfi386
     @skipIfNoSBHeaders