Sketch out a DWARF parser.

This introduces a new library to LLVM: libDebugInfo. It will provide debug information
parsing to LLVM. Much of the design and some of the code is taken from the LLDB project.

It also contains an llvm-dwarfdump tool that can dump the abbrevs and DIEs from an
object file. It can be used to write tests for DWARF input and output easily.

llvm-svn: 139627
diff --git a/llvm/tools/llvm-dwarfdump/CMakeLists.txt b/llvm/tools/llvm-dwarfdump/CMakeLists.txt
new file mode 100644
index 0000000..05aad3f
--- /dev/null
+++ b/llvm/tools/llvm-dwarfdump/CMakeLists.txt
@@ -0,0 +1,8 @@
+set(LLVM_LINK_COMPONENTS
+  DebugInfo
+  Object
+  )
+
+add_llvm_tool(llvm-dwarfdump
+  llvm-dwarfdump.cpp
+  )