use std::copy instead of memcpy for abstraction.
Disable rewrite-tabs.  This speeds up processing of the commentified huge
crazy testcase steve gave me from 20s to 6.6s in a release build.

llvm-svn: 43880
diff --git a/clang/Driver/RewriteTest.cpp b/clang/Driver/RewriteTest.cpp
index 8ff6bc6..a7f1c20 100644
--- a/clang/Driver/RewriteTest.cpp
+++ b/clang/Driver/RewriteTest.cpp
@@ -195,7 +195,9 @@
 
 RewriteTest::~RewriteTest() {
   // Get the top-level buffer that this corresponds to.
-  RewriteTabs();
+  
+  // Rewrite tabs if we care.
+  //RewriteTabs();
   
   // Rewrite Objective-c meta data*
   std::string ResultStr;