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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139627 91177308-0d34-0410-b5e6-96231b3b80d8

lib/DebugInfo/DIContext.cpp

@@ -0,0 +1,24 @@
+//===-- DIContext.cpp -----------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/DIContext.h"
+#include "DWARFContext.h"
+using namespace llvm;
+
+DIContext::~DIContext() {}
+
+DIContext *DIContext::getDWARFContext(bool isLittleEndian,
+                                      StringRef infoSection,
+                                      StringRef abbrevSection,
+                                      StringRef aRangeSection,
+                                      StringRef lineSection,
+                                      StringRef stringSection) {
+  return new DWARFContextInMemory(isLittleEndian, infoSection, abbrevSection,
+                                  aRangeSection, lineSection, stringSection);
+}