Add support for XFAILing valgrind runs with memory leak checking independently

of runs without leak checking.  We add -vg to the triple for non-checked runs,
or -vg_leak for checked runs.  Also use this to XFAIL the TableGen tests, since
tablegen leaks like a sieve.  This includes some valgrindArgs refactoring.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99103 91177308-0d34-0410-b5e6-96231b3b80d8

test/TableGen/IntBitInit.td

@@ -1,4 +1,5 @@
 // RUN: tblgen %s
+// XFAIL: vg_leak
 def {
   bit A = 1;
   int B = A;