split MCSection stuff out to its own .cpp file, add a new
MCSectionWithKind subclass of MCSection.

llvm-svn: 77684
diff --git a/llvm/lib/MC/CMakeLists.txt b/llvm/lib/MC/CMakeLists.txt
index 3dd1e18..82d400b 100644
--- a/llvm/lib/MC/CMakeLists.txt
+++ b/llvm/lib/MC/CMakeLists.txt
@@ -3,6 +3,7 @@
   MCAsmParser.cpp
   MCAsmStreamer.cpp
   MCContext.cpp
+  MCSection.cpp
   MCStreamer.cpp
   TargetAsmParser.cpp
   )