[lldb] Disable failing tests on Linux

rdar://118335574
(cherry picked from commit 159ab5f)

Author: felipepiovezan

Diff for: lldb/test/API/lang/swift/expression/import_search_paths/TestSwiftImportSearchPaths.py

@@ -5,6 +5,7 @@
 import unittest2
 
 
+@skipIfLinux
 class TestSwiftImportSearchPaths(lldbtest.TestBase):
     NO_DEBUG_INFO_TESTCASE = True
     mydir = lldbtest.TestBase.compute_mydir(__file__)

Diff for: lldb/test/Shell/Swift/MissingVFSOverlay.test

@@ -1,5 +1,6 @@
 # Test that error messages from constructing ClangImporter
 # are surfaced to the user.
+# UNSUPPORTED: system-linux
 # REQUIRES: swift
 
 # RUN: rm -rf %t && mkdir %t && cd %t