Move DIContext.h to common DebugInfo location.

This will enable us to create a PDBContext so as to expose some
amount of debug info functionality through a common interace.

Differential Revision: http://reviews.llvm.org/D9205
Reviewed by: Alexey Samsonov

llvm-svn: 235612
diff --git a/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp b/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
index 36061d7..c3988e1 100644
--- a/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
+++ b/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
@@ -14,6 +14,7 @@
 #include "LLVMSymbolize.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Config/config.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Support/Casting.h"
@@ -460,7 +461,7 @@
     Modules.insert(make_pair(ModuleName, (ModuleInfo *)nullptr));
     return nullptr;
   }
-  DIContext *Context = DIContext::getDWARFContext(*Objects.second);
+  DIContext *Context = new DWARFContextInMemory(*Objects.second);
   assert(Context);
   ModuleInfo *Info = new ModuleInfo(Objects.first, Context);
   Modules.insert(make_pair(ModuleName, Info));