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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@43880 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Rewrite/Rewriter.cpp b/Rewrite/Rewriter.cpp
index f068f68..5e6374e 100644
--- a/Rewrite/Rewriter.cpp
+++ b/Rewrite/Rewriter.cpp
@@ -121,7 +121,8 @@
   assert(RealOffset+OrigLength <= Buffer.size() && "Invalid location");
 
   // Overwrite the common piece.
-  memcpy(&Buffer[RealOffset], NewStr, std::min(OrigLength, NewLength));
+  std::copy(NewStr, NewStr+std::min(OrigLength, NewLength),
+            Buffer.begin()+RealOffset);
   
   // If replacing without shifting around, just overwrite the text.
   if (OrigLength == NewLength)