Re-land "[dwarfdump] Add -lookup option"

Add the option to lookup an address in the debug information and print
out the file, function, block and line table details.

Differential revision: https://reviews.llvm.org/D38409

llvm-svn: 316619
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index 65ab594..c3d8ff2 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -440,7 +440,7 @@
   // NULL DIEs don't have siblings.
   if (Die->getAbbreviationDeclarationPtr() == nullptr)
     return DWARFDie();
-  
+
   // Find the next DIE whose depth is the same as the Die's depth.
   for (size_t I = getDIEIndex(Die) + 1, EndIdx = DieArray.size(); I < EndIdx;
        ++I) {