Mark 36 tests as XFAIL:vg_leak in llvm/test/TableGen.

In historical reason, tblgen is not strictly required to be free from memory leaks.
For now, I mark them as XFAIL, they could be fixed, though.

llvm-svn: 194353
diff --git a/llvm/test/TableGen/MultiClassInherit.td b/llvm/test/TableGen/MultiClassInherit.td
index 7a9be3d..04fef2c 100644
--- a/llvm/test/TableGen/MultiClassInherit.td
+++ b/llvm/test/TableGen/MultiClassInherit.td
@@ -1,4 +1,5 @@
 // RUN: llvm-tblgen %s | FileCheck %s
+// XFAIL: vg_leak
 
 // "zing = 4" x 28
 // CHECK: zing = 4