add and document regex support for FileCheck. You can now do stuff like:

; CHECK: movl {{%e[a-z][xi]}}, %eax

or whatever.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82717 91177308-0d34-0410-b5e6-96231b3b80d8

unittests/Support/RegexTest.cpp

@@ -9,6 +9,7 @@
 
 #include "gtest/gtest.h"
 #include "llvm/Support/Regex.h"
+#include "llvm/ADT/SmallVector.h"
 #include <cstring>
 
 using namespace llvm;