Implement LLVM JIT side of GDB JIT debugging interface

include/llvm/Target/TargetOptions.h

Index: include/llvm/Target/TargetOptions.h
===================================================================
--- include/llvm/Target/TargetOptions.h	(revision 82403)
+++ include/llvm/Target/TargetOptions.h	(working copy)
@@ -103,6 +103,10 @@
   /// information should be emitted.
   extern bool SjLjExceptionHandling;
 
+  /// JITEmitDebugInfo - This flag indicates that the JIT should try to emit
+  /// debug information and notify a debugger about it.
+  extern bool JITEmitDebugInfo;
+
   /// UnwindTablesMandatory - This flag indicates that unwind tables should
   /// be emitted for all functions.
   extern bool UnwindTablesMandatory;