Add a new RewriteRope data structure which is a smarter way to represent the text
backing a rewrite buffer than using an std::vector<char>.  This class was hacked
together very quickly and needs to be cleaned up, but it seems to work.  It speeds
up rewriting a a 7M file from 6.43s to 0.24s on my machine.  The impl could also
be made to be a lot more algorithmically sound.

This produces identical output to using vector on this testcase, if it causes a
problems or bugs are encountered, it can be disabled by changing the 
RewriteBuffer::Buffer typedef back.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@43884 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/clang.xcodeproj/project.pbxproj b/clang.xcodeproj/project.pbxproj
index a0ddddf..b9eb859 100644
--- a/clang.xcodeproj/project.pbxproj
+++ b/clang.xcodeproj/project.pbxproj
@@ -291,6 +291,7 @@
 		DE46BF270AE0A82D00CC047C /* TargetInfo.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; path = TargetInfo.h; sourceTree = "<group>"; };
 		DE4772F90C10EAE5002239E8 /* CGStmt.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = CGStmt.cpp; path = CodeGen/CGStmt.cpp; sourceTree = "<group>"; };
 		DE4772FB0C10EAEC002239E8 /* CGExpr.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = CGExpr.cpp; path = CodeGen/CGExpr.cpp; sourceTree = "<group>"; };
+		DE53370B0CE2D96F00D9A028 /* RewriteRope.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = RewriteRope.h; path = clang/Rewrite/RewriteRope.h; sourceTree = "<group>"; };
 		DE5932CD0AD60FF400BC794C /* clang.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = clang.cpp; path = Driver/clang.cpp; sourceTree = "<group>"; };
 		DE5932CE0AD60FF400BC794C /* clang.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = clang.h; path = Driver/clang.h; sourceTree = "<group>"; };
 		DE5932CF0AD60FF400BC794C /* PrintParserCallbacks.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = PrintParserCallbacks.cpp; path = Driver/PrintParserCallbacks.cpp; sourceTree = "<group>"; };
@@ -723,6 +724,7 @@
 			isa = PBXGroup;
 			children = (
 				DEF7D9F60C9C8B1A0001F598 /* Rewriter.h */,
+				DE53370B0CE2D96F00D9A028 /* RewriteRope.h */,
 			);
 			name = Rewrite;
 			sourceTree = "<group>";